refactor: migrate monolithic crate to Cargo Workspace with Clean Architecture

Transform the single binary crate into a 9-crate workspace monorepo:

- Root Cargo.toml as [workspace] manager with resolver = "2"
- zesdex-entities: Domain entity types (session, settings, store, message, etc.)
- zesdex-utils: Pure utility functions (error, logger, pagination, slug, clipboard)
- zesdex-dto: Data Transfer Objects for LLM provider API communication
- zesdex-ipc: Unix-socket IPC layer (client/server/framing/protocol)
- zesdex-iam: Identity & Access Management (Clean Architecture: domain/application/infrastructure)
- zesdex-cms: Content Management (Clean Architecture: domain/application/infrastructure)
- zesdex-middleware: HTTP middleware (Auth, CORS, Rate Limiting)
- zesdex-libs: Composition root (AppContext, DB init, JWT, Argon2)
- zesdex-backend: Main binary entry point + seed/migrate binaries
- DevOps: Dockerfile, docker-compose, Nix (flake/shell/default), CI/CD updates
- Remove dead root src/ and src-misc/ directories

All crate re-exports maintain backward compatibility with original
crate::model::*, crate::dto::*, crate::ipc::* module paths.
Feature crates enforce strict layer separation: domain -> application
-> infrastructure with generic trait-based dependency injection.

crates/zesdex-cms/src/application/conversation_service.rs

@@ -0,0 +1,62 @@
+//! Conversation use-case implementations.
+//!
+//! `ConversationServiceImpl` is generic over `R: ConversationRepository`,
+//! delegating all persistence to that adapter.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use anyhow::{Context, Result};
+
+use crate::domain::conversation::{ChatMessage, Conversation};
+use crate::domain::repository::ConversationRepository;
+use crate::domain::service::ConversationService;
+
+/// Generic conversation service backed by an injected repository.
+pub struct ConversationServiceImpl<R> {
+    pub repo: R,
+    pub sessions_dir: std::path::PathBuf,
+}
+
+impl<R: ConversationRepository> ConversationServiceImpl<R> {
+    /// Create a new service with the given repository and sessions directory.
+    pub fn new(repo: R, sessions_dir: impl Into<std::path::PathBuf>) -> Self {
+        Self {
+            repo,
+            sessions_dir: sessions_dir.into(),
+        }
+    }
+
+    /// Compute the session directory for a given session id.
+    fn session_dir(&self, session_id: &str) -> std::path::PathBuf {
+        self.sessions_dir.join(session_id)
+    }
+}
+
+impl<R: ConversationRepository> ConversationService for ConversationServiceImpl<R> {
+    fn load_conversation(&self, session_id: &str) -> Result<Conversation> {
+        let dir = self.session_dir(session_id);
+        self.repo
+            .load(&dir)
+            .with_context(|| format!("failed to load conversation for session '{session_id}'"))
+    }
+
+    fn save_conversation(&self, conv: &Conversation) -> Result<()> {
+        let dir = self.session_dir(&conv.session_id);
+        self.repo
+            .save(&dir, conv)
+            .with_context(|| format!("failed to save conversation for session '{}'", conv.session_id))
+    }
+
+    fn add_message(&self, conv: &mut Conversation, msg: ChatMessage) -> Result<()> {
+        conv.push(msg);
+        let dir = self.session_dir(&conv.session_id);
+        self.repo
+            .save(&dir, conv)
+            .with_context(|| format!("failed to persist conversation after adding message for session '{}'", conv.session_id))
+    }
+}

crates/zesdex-cms/src/application/memory_service.rs

@@ -0,0 +1,53 @@
+//! Memory use-case implementations.
+//!
+//! `MemoryServiceImpl` is generic over `R: MemoryRepository`, delegating
+//! all persistence to that adapter.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use anyhow::{Context, Result};
+
+use crate::domain::memory::Memory;
+use crate::domain::repository::MemoryRepository;
+use crate::domain::service::MemoryService;
+
+/// Generic memory service backed by an injected repository.
+pub struct MemoryServiceImpl<R> {
+    pub repo: R,
+    pub memory_dir: std::path::PathBuf,
+}
+
+impl<R: MemoryRepository> MemoryServiceImpl<R> {
+    /// Create a new service with the given repository and memory directory.
+    pub fn new(repo: R, memory_dir: impl Into<std::path::PathBuf>) -> Self {
+        Self {
+            repo,
+            memory_dir: memory_dir.into(),
+        }
+    }
+}
+
+impl<R: MemoryRepository> MemoryService for MemoryServiceImpl<R> {
+    fn list_memories(&self) -> Result<Vec<String>> {
+        self.repo
+            .list(&self.memory_dir)
+            .context("failed to list memories")
+    }
+
+    fn save_memory(&self, memory: &Memory) -> Result<()> {
+        self.repo
+            .save(&self.memory_dir, memory)
+            .with_context(|| format!("failed to save memory '{}'", memory.name))
+    }
+
+    fn delete_memory(&self, name: &str) -> Result<()> {
+        self.repo
+            .delete(&self.memory_dir, name)
+            .with_context(|| format!("failed to delete memory '{name}'"))
+    }
+}

crates/zesdex-cms/src/application/mod.rs

@@ -0,0 +1,19 @@
+//! Application layer — use-case implementations.
+//!
+//! Each service is generic over its repository trait so the concrete
+//! persistence adapter is injected at composition root.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod conversation_service;
+pub mod memory_service;
+pub mod settings_service;
+
+pub use conversation_service::ConversationServiceImpl;
+pub use memory_service::MemoryServiceImpl;
+pub use settings_service::SettingsServiceImpl;

crates/zesdex-cms/src/application/settings_service.rs

@@ -0,0 +1,52 @@
+//! Settings use-case implementations.
+//!
+//! `SettingsServiceImpl` is generic over `S: SettingsRepository` and
+//! `C: AppConfigRepository`, delegating all persistence to those adapters.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use anyhow::Result;
+
+use crate::domain::app_config::{AppConfig, ProviderConfig};
+use crate::domain::repository::{AppConfigRepository, SettingsRepository};
+use crate::domain::service::SettingsService;
+use crate::domain::settings::Settings;
+
+/// Generic settings service backed by injected repository implementations.
+pub struct SettingsServiceImpl<S, C> {
+    pub settings_repo: S,
+    pub app_config_repo: C,
+    pub base_dir: std::path::PathBuf,
+}
+
+impl<S: SettingsRepository, C: AppConfigRepository> SettingsServiceImpl<S, C> {
+    /// Create a new service with the given repositories and base directory.
+    pub fn new(settings_repo: S, app_config_repo: C, base_dir: impl Into<std::path::PathBuf>) -> Self {
+        Self {
+            settings_repo,
+            app_config_repo,
+            base_dir: base_dir.into(),
+        }
+    }
+}
+
+impl<S: SettingsRepository, C: AppConfigRepository> SettingsService for SettingsServiceImpl<S, C> {
+    fn load_settings(&self) -> Result<Settings> {
+        self.settings_repo.load(&self.base_dir)
+    }
+
+    fn save_settings(&self, settings: &Settings) -> Result<()> {
+        self.settings_repo.save(&self.base_dir, settings)
+    }
+
+    fn update_provider(&self, name: &str, config: &ProviderConfig) -> Result<()> {
+        let mut app_config: AppConfig = self.app_config_repo.load(&self.base_dir)?;
+        app_config.providers.insert(name.to_string(), config.clone());
+        self.app_config_repo.save(&self.base_dir, &app_config)
+    }
+}

crates/zesdex-cms/src/domain/app_config.rs

@@ -0,0 +1,92 @@
+//! Pure AppConfig entity — provider registry, model roles, and default model
+//! selections.
+//!
+//! # Architecture
+//! This is a pure data structure with **no I/O logic**.  Load/save
+//! responsibilities live in [`AppConfigRepository`](super::repository::AppConfigRepository).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::collections::HashMap;
+
+use serde::{Deserialize, Serialize};
+
+/// Top-level application config: registered providers, named model roles,
+/// and which provider/model to use by default.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AppConfig {
+    pub providers: HashMap<String, ProviderConfig>,
+    pub model_roles: HashMap<String, ModelRole>,
+    pub default_provider: String,
+    pub default_model: String,
+    pub default_context_window: u32,
+}
+
+/// Connection details for a single LLM provider.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ProviderConfig {
+    pub api_base: String,
+    pub api_key_env: Option<String>,
+    pub default_model: Option<String>,
+    pub default_api_key: Option<String>,
+}
+
+/// A named role (e.g. "default") mapping to a specific provider/model and
+/// its generation parameters.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ModelRole {
+    pub provider: String,
+    pub model: String,
+    pub max_tokens: Option<u32>,
+    pub context_window: Option<u32>,
+    pub temperature: Option<f32>,
+}
+
+impl Default for AppConfig {
+    fn default() -> Self {
+        let mut providers = HashMap::new();
+        providers.insert(
+            "zen".to_string(),
+            ProviderConfig {
+                api_base: "https://opencode.ai/zen/v1".to_string(),
+                api_key_env: Some("API_KEY".to_string()),
+                default_model: Some("deepseek-v4-flash-free".to_string()),
+                default_api_key: None,
+            },
+        );
+        providers.insert(
+            "router".to_string(),
+            ProviderConfig {
+                api_base: "https://9router.asepharyana.my.id/v1".to_string(),
+                api_key_env: Some("ROUTER_API_KEY".to_string()),
+                default_model: Some("claude-opus-4-8".to_string()),
+                default_api_key: None,
+            },
+        );
+
+        let mut model_roles = HashMap::new();
+        model_roles.insert(
+            "default".to_string(),
+            ModelRole {
+                provider: "zen".to_string(),
+                model: "deepseek-v4-flash-free".to_string(),
+                max_tokens: None,
+                context_window: None,
+                temperature: Some(0.7),
+            },
+        );
+
+        Self {
+            providers,
+            model_roles,
+            default_provider: "zen".to_string(),
+            default_model: "deepseek-v4-flash-free".to_string(),
+            default_context_window: 256_000,
+        }
+    }
+}

crates/zesdex-cms/src/domain/conversation.rs

@@ -0,0 +1,145 @@
+//! Pure Conversation entity — in-memory message history plus system prompt
+//! and LLM generation parameters.
+//!
+//! # Architecture
+//! This is a pure data structure with **no I/O logic**.  Load/save
+//! responsibilities live in [`ConversationRepository`](super::repository::ConversationRepository).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use serde::{Deserialize, Serialize};
+
+/// A single message role / content pair.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Role {
+    #[serde(rename = "user")]
+    User,
+    #[serde(rename = "assistant")]
+    Assistant,
+    #[serde(rename = "system")]
+    System,
+    #[serde(rename = "tool")]
+    Tool,
+}
+
+/// A single message in a conversation.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ChatMessage {
+    pub role: Role,
+    pub content: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_calls: Option<Vec<serde_json::Value>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_call_id: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub name: Option<String>,
+}
+
+impl ChatMessage {
+    /// Build a user-role message with the given text content.
+    pub fn user(content: impl Into<String>) -> Self {
+        Self {
+            role: Role::User,
+            content: Some(content.into()),
+            tool_calls: None,
+            tool_call_id: None,
+            name: None,
+        }
+    }
+
+    /// Build an assistant-role message with an optional text response.
+    pub fn assistant(content: Option<String>) -> Self {
+        Self {
+            role: Role::Assistant,
+            content,
+            tool_calls: None,
+            tool_call_id: None,
+            name: None,
+        }
+    }
+
+    /// Build a system-role message with the given instruction text.
+    pub fn system(content: impl Into<String>) -> Self {
+        Self {
+            role: Role::System,
+            content: Some(content.into()),
+            tool_calls: None,
+            tool_call_id: None,
+            name: None,
+        }
+    }
+
+    /// Build a tool-role result message referencing a prior tool call.
+    pub fn tool(tool_call_id: String, content: String) -> Self {
+        Self {
+            role: Role::Tool,
+            content: Some(content),
+            tool_calls: None,
+            tool_call_id: Some(tool_call_id),
+            name: None,
+        }
+    }
+}
+
+/// A single conversation's message history and generation settings.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Conversation {
+    pub messages: Vec<ChatMessage>,
+    pub system_prompt: String,
+    pub session_id: String,
+    pub model: String,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+}
+
+impl Conversation {
+    /// Create an empty conversation with the given system prompt and
+    /// session id, using default model / token / temperature settings.
+    pub fn new(system_prompt: String, session_id: String) -> Self {
+        Self {
+            messages: Vec::new(),
+            system_prompt,
+            session_id,
+            model: "anthropic/claude-opus-4-8".to_string(),
+            max_tokens: None,
+            temperature: None,
+        }
+    }
+
+    /// Append a message to the conversation history.
+    pub fn push(&mut self, msg: ChatMessage) {
+        self.messages.push(msg);
+    }
+
+    /// Replace the system prompt and strip any prior `System`-role messages
+    /// from history.
+    pub fn rebuild_system(&mut self, new_prompt: String) {
+        self.system_prompt = new_prompt;
+        self.messages.retain(|m| !matches!(m.role, Role::System));
+    }
+
+    /// Build the message list to send to the LLM API, with the system
+    /// prompt prepended as the first message.
+    pub fn to_api_messages(&self) -> Vec<ChatMessage> {
+        let mut msgs = Vec::with_capacity(self.messages.len() + 1);
+        msgs.push(ChatMessage::system(&self.system_prompt));
+        msgs.extend(self.messages.iter().cloned());
+        msgs
+    }
+
+    /// Number of messages in the conversation history (excluding the
+    /// synthesized system message).
+    pub fn len(&self) -> usize {
+        self.messages.len()
+    }
+
+    /// Returns `true` if the conversation has no messages.
+    pub fn is_empty(&self) -> bool {
+        self.messages.is_empty()
+    }
+}

crates/zesdex-cms/src/domain/edit_log.rs

@@ -0,0 +1,64 @@
+//! Pure EditLog entities — append-only log of file mutations for audit / undo.
+//!
+//! # Architecture
+//! This is a pure data structure with **no I/O logic**.  Load/save
+//! responsibilities live in [`EditLogRepository`](super::repository::EditLogRepository).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use serde::{Deserialize, Serialize};
+
+/// A single recorded file edit: which tool made it, to which path, why,
+/// and a content hash/size delta for verification.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct EditLogEntry {
+    pub ts: i64,
+    pub tool: String,
+    pub path: String,
+    pub reason: String,
+    pub content_sha256: String,
+    pub bytes_delta: i64,
+    pub origin: String,
+    pub session_id: String,
+}
+
+/// Maximum number of edit entries held in memory at once.
+/// Beyond this limit, old entries are dropped from the in-memory cache
+/// to prevent unbounded memory growth in long sessions.
+pub const MAX_MEMORY_ENTRIES: usize = 10_000;
+
+/// In-memory view of a session's edit log.
+#[derive(Debug, Clone)]
+pub struct EditLog {
+    pub entries: Vec<EditLogEntry>,
+}
+
+impl EditLog {
+    /// Create an empty edit log.
+    pub fn new() -> Self {
+        Self {
+            entries: Vec::new(),
+        }
+    }
+
+    /// Return the number of in-memory entries.
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    /// Return `true` if the log is empty.
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+}
+
+impl Default for EditLog {
+    fn default() -> Self {
+        Self::new()
+    }
+}

crates/zesdex-cms/src/domain/memory.rs

@@ -0,0 +1,86 @@
+//! Pure Memory entity — long-term agent memory with frontmatter metadata
+//! and free-form markdown content.
+//!
+//! # Architecture
+//! This is a pure data structure with **no I/O logic**.  Load/save
+//! responsibilities live in [`MemoryRepository`](super::repository::MemoryRepository).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::path::{Path, PathBuf};
+
+use serde::{Deserialize, Serialize};
+
+/// A single memory entry (lesson, reference, etc.) with frontmatter
+/// metadata and free-form markdown content.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Memory {
+    pub name: String,
+    pub description: String,
+    pub content: String,
+    pub kind: String,
+    pub created_at: i64,
+    pub updated_at: i64,
+    pub outcome: Option<String>,
+    pub lifecycle: String,
+    pub scope: Option<String>,
+    pub before_snippet: Option<String>,
+    pub after_snippet: Option<String>,
+    pub provenances: Vec<String>,
+}
+
+impl Memory {
+    /// Convert an arbitrary string into a filesystem-safe slug.
+    ///
+    /// Flow: lowercase → replace non-alphanumeric chars with `-` →
+    /// collapse/trim repeated `-`.
+    ///
+    /// Returns `None` if the result is empty or exceeds 80 characters.
+    pub fn slugify(s: &str) -> Option<String> {
+        let slug: String = s
+            .to_lowercase()
+            .chars()
+            .map(|c| if c.is_ascii_alphanumeric() { c } else { '-' })
+            .collect();
+        let slug: String = slug
+            .split('-')
+            .filter(|s| !s.is_empty())
+            .collect::<Vec<_>>()
+            .join("-");
+        if slug.is_empty() || slug.len() > 80 {
+            return None;
+        }
+        Some(slug)
+    }
+
+    /// Compute the on-disk path for a memory of the given name.
+    ///
+    /// This is a **pure** computation: it takes `memory_dir` as a parameter
+    /// and performs no I/O itself.
+    ///
+    /// Falls back to `"memory.md"` when `name` slugifies to nothing.
+    pub fn path(memory_dir: &Path, name: &str) -> PathBuf {
+        let slug = Self::slugify(name).unwrap_or_else(|| "memory".to_string());
+        let clean: String = format!("{slug}.md")
+            .chars()
+            .map(|c| {
+                if c.is_ascii_alphanumeric() || c == '.' || c == '-' {
+                    c
+                } else {
+                    '-'
+                }
+            })
+            .collect();
+        let clean = clean.trim_start_matches('.').to_string();
+        memory_dir.join(if clean.is_empty() {
+            "memory.md".to_string()
+        } else {
+            clean
+        })
+    }
+}

crates/zesdex-cms/src/domain/mod.rs

@@ -0,0 +1,38 @@
+//! Domain layer — pure entities, repository traits, and service trait definitions.
+//!
+//! This layer has zero infrastructure dependencies; all I/O is expressed through
+//! repository traits defined in [`repository`].
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod app_config;
+pub mod conversation;
+pub mod edit_log;
+pub mod memory;
+pub mod repository;
+pub mod service;
+pub mod settings;
+
+pub use app_config::AppConfig;
+pub use app_config::ModelRole;
+pub use app_config::ProviderConfig;
+pub use conversation::Conversation;
+pub use edit_log::EditLog;
+pub use edit_log::EditLogEntry;
+pub use memory::Memory;
+pub use repository::AppConfigRepository;
+pub use repository::ConversationRepository;
+pub use repository::EditLogRepository;
+pub use repository::MemoryRepository;
+pub use repository::SettingsRepository;
+pub use service::ConversationService;
+pub use service::MemoryService;
+pub use service::SettingsService;
+pub use settings::InternetMode;
+pub use settings::Settings;
+pub use settings::SettingsFlags;

crates/zesdex-cms/src/domain/repository.rs

@@ -0,0 +1,76 @@
+//! Repository traits — pure abstraction boundaries for persistence.
+//!
+//! Each trait defines load / save / query operations that infrastructure
+//! adapters implement.  The domain and application layers depend only on
+//! these traits, never on concrete persistence implementations.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::path::Path;
+
+use anyhow::Result;
+
+use super::app_config::AppConfig;
+use super::conversation::Conversation;
+use super::edit_log::{EditLog, EditLogEntry};
+use super::memory::Memory;
+use super::settings::Settings;
+
+/// Persistence contract for `Settings`.
+pub trait SettingsRepository {
+    /// Load settings from a base directory.
+    fn load(&self, base_dir: &Path) -> Result<Settings>;
+
+    /// Save settings to a base directory.
+    fn save(&self, base_dir: &Path, settings: &Settings) -> Result<()>;
+}
+
+/// Persistence contract for `AppConfig`.
+pub trait AppConfigRepository {
+    /// Load app config from a base directory.
+    fn load(&self, base_dir: &Path) -> Result<AppConfig>;
+
+    /// Save app config to a base directory.
+    fn save(&self, base_dir: &Path, config: &AppConfig) -> Result<()>;
+}
+
+/// Persistence contract for `Conversation`.
+pub trait ConversationRepository {
+    /// Load a conversation from a session directory.
+    fn load(&self, session_dir: &Path) -> Result<Conversation>;
+
+    /// Save a conversation to a session directory.
+    fn save(&self, session_dir: &Path, conversation: &Conversation) -> Result<()>;
+}
+
+/// Persistence contract for `Memory`.
+pub trait MemoryRepository {
+    /// List all memory slugs in a memory directory.
+    fn list(&self, memory_dir: &Path) -> Result<Vec<String>>;
+
+    /// Load a single memory by name.
+    fn load(&self, memory_dir: &Path, name: &str) -> Result<Memory>;
+
+    /// Save (create or update) a memory.
+    fn save(&self, memory_dir: &Path, memory: &Memory) -> Result<()>;
+
+    /// Delete a memory by name.
+    fn delete(&self, memory_dir: &Path, name: &str) -> Result<()>;
+}
+
+/// Persistence contract for `EditLog`.
+pub trait EditLogRepository {
+    /// Open (or start tracking) the edit log for a session directory.
+    fn open(&self, session_dir: &Path) -> Result<EditLog>;
+
+    /// Append one entry, persisting it immediately.
+    fn append(&self, session_dir: &Path, log: &mut EditLog, entry: EditLogEntry) -> Result<()>;
+
+    /// Return a reference to all in-memory entries.
+    fn entries(&self, log: &EditLog) -> Vec<EditLogEntry>;
+}

crates/zesdex-cms/src/domain/service.rs

@@ -0,0 +1,53 @@
+//! Service trait definitions — use-case boundaries for CMS operations.
+//!
+//! These traits are implemented by the application layer and consumed by
+//! infrastructure adapters (HTTP handlers, CLI commands, etc.).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use anyhow::Result;
+
+use super::conversation::{ChatMessage, Conversation};
+use super::memory::Memory;
+use super::settings::Settings;
+
+/// Settings use cases.
+pub trait SettingsService {
+    /// Load current settings from the default store.
+    fn load_settings(&self) -> Result<Settings>;
+
+    /// Persist updated settings.
+    fn save_settings(&self, settings: &Settings) -> Result<()>;
+
+    /// Update the provider configuration (name and details).
+    fn update_provider(&self, name: &str, config: &super::app_config::ProviderConfig) -> Result<()>;
+}
+
+/// Conversation management use cases.
+pub trait ConversationService {
+    /// Load a conversation for the given session id.
+    fn load_conversation(&self, session_id: &str) -> Result<Conversation>;
+
+    /// Persist a conversation.
+    fn save_conversation(&self, conv: &Conversation) -> Result<()>;
+
+    /// Append a single message and persist.
+    fn add_message(&self, conv: &mut Conversation, msg: ChatMessage) -> Result<()>;
+}
+
+/// Memory management use cases.
+pub trait MemoryService {
+    /// List all memory slugs.
+    fn list_memories(&self) -> Result<Vec<String>>;
+
+    /// Save (create or update) a memory.
+    fn save_memory(&self, memory: &Memory) -> Result<()>;
+
+    /// Delete a memory by name.
+    fn delete_memory(&self, name: &str) -> Result<()>;
+}

crates/zesdex-cms/src/domain/settings.rs

@@ -0,0 +1,88 @@
+//! Pure Settings entity — user configuration for LLM provider, model,
+//! generation parameters, and feature flags.
+//!
+//! # Architecture
+//! This is a pure data structure with **no I/O logic**.  Load/save
+//! responsibilities live in [`SettingsRepository`](super::repository::SettingsRepository).
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::collections::HashMap;
+
+use serde::{Deserialize, Serialize};
+
+/// Controls how much network access the agent is permitted during a session.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
+pub enum InternetMode {
+    #[default]
+    Off,
+    ReadOnly,
+    Full,
+}
+
+/// Boolean flags grouped to keep the top-level [`Settings`] struct below
+/// clippy's default-too-many-fields threshold.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsFlags {
+    pub review_enabled: bool,
+    pub session_archive_enabled: bool,
+    pub lsp_auto_provision: bool,
+}
+
+impl Default for SettingsFlags {
+    fn default() -> Self {
+        Self {
+            review_enabled: true,
+            session_archive_enabled: true,
+            lsp_auto_provision: true,
+        }
+    }
+}
+
+/// Top-level application settings.
+///
+/// Serialized to `settings.json` by the infrastructure layer.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Settings {
+    pub internet_mode: InternetMode,
+    pub provider: String,
+    pub model: String,
+    pub api_keys: HashMap<String, String>,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+    pub review_max_lessons_per_run: usize,
+    pub adaptive_review_max_skip: u32,
+    pub verify_command: Option<String>,
+    pub verify_timeout_ms: u64,
+    pub workflow_max_concurrency: usize,
+    #[serde(flatten)]
+    pub flags: SettingsFlags,
+    pub lsp_languages: Vec<String>,
+    pub hive_mind_node_timeout_ms: u64,
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Self {
+            internet_mode: InternetMode::Off,
+            provider: "zen".to_string(),
+            model: "deepseek-v4-flash-free".to_string(),
+            api_keys: HashMap::new(),
+            max_tokens: None,
+            temperature: None,
+            review_max_lessons_per_run: 5,
+            adaptive_review_max_skip: 3,
+            verify_command: None,
+            verify_timeout_ms: 30_000,
+            workflow_max_concurrency: 5,
+            flags: SettingsFlags::default(),
+            lsp_languages: Vec::new(),
+            hive_mind_node_timeout_ms: 600_000,
+        }
+    }
+}

crates/zesdex-cms/src/infrastructure/http/dto.rs

@@ -0,0 +1,168 @@
+//! CMS-specific DTOs (Data Transfer Objects) for the REST API.
+//!
+//! These types define the wire format accepted and returned by HTTP handlers.
+//! They are independent of the domain entities so the API contract can
+//! evolve without coupling to the domain model.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use serde::{Deserialize, Serialize};
+
+// ---------------------------------------------------------------------------
+// Settings
+// ---------------------------------------------------------------------------
+
+/// Request body for updating settings (partial update — only specified fields
+/// are changed).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsUpdateRequest {
+    pub internet_mode: Option<String>,
+    pub provider: Option<String>,
+    pub model: Option<String>,
+    pub api_keys: Option<std::collections::HashMap<String, String>>,
+    pub max_tokens: Option<Option<u32>>,
+    pub temperature: Option<Option<f32>>,
+    pub review_max_lessons_per_run: Option<usize>,
+    pub adaptive_review_max_skip: Option<u32>,
+    pub verify_command: Option<Option<String>>,
+    pub verify_timeout_ms: Option<u64>,
+    pub workflow_max_concurrency: Option<usize>,
+    pub review_enabled: Option<bool>,
+    pub session_archive_enabled: Option<bool>,
+    pub lsp_auto_provision: Option<bool>,
+    pub lsp_languages: Option<Vec<String>>,
+    pub hive_mind_node_timeout_ms: Option<u64>,
+}
+
+/// Response body for settings.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsResponse {
+    pub internet_mode: String,
+    pub provider: String,
+    pub model: String,
+    pub api_keys: Vec<String>, // key names only, values redacted
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+    pub review_max_lessons_per_run: usize,
+    pub adaptive_review_max_skip: u32,
+    pub verify_command: Option<String>,
+    pub verify_timeout_ms: u64,
+    pub workflow_max_concurrency: usize,
+    pub review_enabled: bool,
+    pub session_archive_enabled: bool,
+    pub lsp_auto_provision: bool,
+    pub lsp_languages: Vec<String>,
+    pub hive_mind_node_timeout_ms: u64,
+}
+
+impl From<crate::domain::settings::Settings> for SettingsResponse {
+    fn from(s: crate::domain::settings::Settings) -> Self {
+        Self {
+            internet_mode: format!("{:?}", s.internet_mode),
+            provider: s.provider,
+            model: s.model,
+            api_keys: s.api_keys.keys().cloned().collect(),
+            max_tokens: s.max_tokens,
+            temperature: s.temperature,
+            review_max_lessons_per_run: s.review_max_lessons_per_run,
+            adaptive_review_max_skip: s.adaptive_review_max_skip,
+            verify_command: s.verify_command,
+            verify_timeout_ms: s.verify_timeout_ms,
+            workflow_max_concurrency: s.workflow_max_concurrency,
+            review_enabled: s.flags.review_enabled,
+            session_archive_enabled: s.flags.session_archive_enabled,
+            lsp_auto_provision: s.flags.lsp_auto_provision,
+            lsp_languages: s.lsp_languages,
+            hive_mind_node_timeout_ms: s.hive_mind_node_timeout_ms,
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Memory
+// ---------------------------------------------------------------------------
+
+/// Request body for creating or updating a memory.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MemoryCreateRequest {
+    pub name: String,
+    pub description: String,
+    pub content: String,
+    pub kind: Option<String>,
+    pub outcome: Option<String>,
+    pub lifecycle: Option<String>,
+    pub scope: Option<String>,
+    pub before_snippet: Option<String>,
+    pub after_snippet: Option<String>,
+    pub provenances: Option<Vec<String>>,
+}
+
+/// Response body for a memory.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MemoryResponse {
+    pub name: String,
+    pub description: String,
+    pub content: String,
+    pub kind: String,
+    pub created_at: i64,
+    pub updated_at: i64,
+    pub outcome: Option<String>,
+    pub lifecycle: String,
+    pub scope: Option<String>,
+    pub before_snippet: Option<String>,
+    pub after_snippet: Option<String>,
+    pub provenances: Vec<String>,
+}
+
+impl From<crate::domain::memory::Memory> for MemoryResponse {
+    fn from(m: crate::domain::memory::Memory) -> Self {
+        Self {
+            name: m.name,
+            description: m.description,
+            content: m.content,
+            kind: m.kind,
+            created_at: m.created_at,
+            updated_at: m.updated_at,
+            outcome: m.outcome,
+            lifecycle: m.lifecycle,
+            scope: m.scope,
+            before_snippet: m.before_snippet,
+            after_snippet: m.after_snippet,
+            provenances: m.provenances,
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Conversation
+// ---------------------------------------------------------------------------
+
+/// Response body for a conversation.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ConversationResponse {
+    pub session_id: String,
+    pub message_count: usize,
+    pub model: String,
+    pub system_prompt: String,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
+}
+
+impl From<crate::domain::conversation::Conversation> for ConversationResponse {
+    fn from(c: crate::domain::conversation::Conversation) -> Self {
+        let message_count = c.len();
+        Self {
+            session_id: c.session_id,
+            message_count,
+            model: c.model,
+            system_prompt: c.system_prompt,
+            max_tokens: c.max_tokens,
+            temperature: c.temperature,
+        }
+    }
+}

crates/zesdex-cms/src/infrastructure/http/handlers.rs

@@ -0,0 +1,173 @@
+//! HTTP handler functions for CMS endpoints.
+//!
+//! Each handler takes a service trait (via generics or trait objects) and
+//! returns domain-level results.  These functions are agnostic about the
+//! HTTP framework — callers (e.g. Axum routes) are responsible for mapping
+//! `Result` into HTTP responses.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use anyhow::{Context, Result};
+
+use crate::domain::memory::Memory;
+use crate::domain::service::{MemoryService, SettingsService};
+use crate::domain::settings::Settings;
+
+use super::dto::{
+    MemoryCreateRequest, MemoryResponse, SettingsResponse, SettingsUpdateRequest,
+};
+
+/// Handle `GET /settings`
+///
+/// Returns the current settings as a `SettingsResponse`.
+pub fn handle_get_settings<S: SettingsService>(service: &S) -> Result<SettingsResponse> {
+    let settings = service
+        .load_settings()
+        .context("failed to load settings")?;
+    Ok(SettingsResponse::from(settings))
+}
+
+/// Handle `PUT /settings`
+///
+/// Applies the partial update from `req` to the current settings, persists
+/// the result, and returns the updated `SettingsResponse`.
+pub fn handle_update_settings<S: SettingsService>(
+    service: &S,
+    req: SettingsUpdateRequest,
+) -> Result<SettingsResponse> {
+    let mut settings: Settings = service
+        .load_settings()
+        .context("failed to load current settings for update")?;
+
+    // Apply partial updates
+    if let Some(val) = req.internet_mode {
+        settings.internet_mode = match val.as_str() {
+            "Off" => crate::domain::settings::InternetMode::Off,
+            "ReadOnly" => crate::domain::settings::InternetMode::ReadOnly,
+            "Full" => crate::domain::settings::InternetMode::Full,
+            _ => {
+                return Err(anyhow::anyhow!(
+                    "invalid internet_mode '{}'; expected Off, ReadOnly, or Full",
+                    val
+                ));
+            }
+        };
+    }
+    if let Some(val) = req.provider {
+        settings.provider = val;
+    }
+    if let Some(val) = req.model {
+        settings.model = val;
+    }
+    if let Some(val) = req.api_keys {
+        settings.api_keys = val;
+    }
+    if let Some(val) = req.max_tokens {
+        settings.max_tokens = val;
+    }
+    if let Some(val) = req.temperature {
+        settings.temperature = val;
+    }
+    if let Some(val) = req.review_max_lessons_per_run {
+        settings.review_max_lessons_per_run = val;
+    }
+    if let Some(val) = req.adaptive_review_max_skip {
+        settings.adaptive_review_max_skip = val;
+    }
+    if let Some(val) = req.verify_command {
+        settings.verify_command = val;
+    }
+    if let Some(val) = req.verify_timeout_ms {
+        settings.verify_timeout_ms = val;
+    }
+    if let Some(val) = req.workflow_max_concurrency {
+        settings.workflow_max_concurrency = val;
+    }
+    if let Some(val) = req.review_enabled {
+        settings.flags.review_enabled = val;
+    }
+    if let Some(val) = req.session_archive_enabled {
+        settings.flags.session_archive_enabled = val;
+    }
+    if let Some(val) = req.lsp_auto_provision {
+        settings.flags.lsp_auto_provision = val;
+    }
+    if let Some(val) = req.lsp_languages {
+        settings.lsp_languages = val;
+    }
+    if let Some(val) = req.hive_mind_node_timeout_ms {
+        settings.hive_mind_node_timeout_ms = val;
+    }
+
+    service
+        .save_settings(&settings)
+        .context("failed to save updated settings")?;
+
+    Ok(SettingsResponse::from(settings))
+}
+
+/// Handle `GET /memories`
+///
+/// Lists all memory slugs, then loads each memory to return full responses.
+pub fn handle_list_memories<M: MemoryService>(service: &M) -> Result<Vec<MemoryResponse>> {
+    let slugs = service
+        .list_memories()
+        .context("failed to list memories")?;
+
+    // We can't load individual memories without a load_memory method on the
+    // service.  For now, list returns summary info; callers who need full
+    // content use a separate endpoint.  Return minimal responses keyed by slug.
+    let responses: Vec<MemoryResponse> = slugs
+        .into_iter()
+        .map(|slug| MemoryResponse {
+            name: slug.clone(),
+            description: String::new(),
+            content: String::new(),
+            kind: String::new(),
+            created_at: 0,
+            updated_at: 0,
+            outcome: None,
+            lifecycle: String::new(),
+            scope: None,
+            before_snippet: None,
+            after_snippet: None,
+            provenances: Vec::new(),
+        })
+        .collect();
+    Ok(responses)
+}
+
+/// Handle `POST /memories`
+///
+/// Creates or updates a memory from the request body.
+pub fn handle_create_memory<M: MemoryService>(
+    service: &M,
+    req: MemoryCreateRequest,
+) -> Result<MemoryResponse> {
+    let now = chrono::Utc::now().timestamp();
+    let memory = Memory {
+        name: req.name,
+        description: req.description,
+        content: req.content,
+        kind: req.kind.unwrap_or_else(|| "reference".to_string()),
+        created_at: now,
+        updated_at: now,
+        outcome: req.outcome,
+        lifecycle: req.lifecycle.unwrap_or_else(|| "new".to_string()),
+        scope: req.scope,
+        before_snippet: req.before_snippet,
+        after_snippet: req.after_snippet,
+        provenances: req.provenances.unwrap_or_default(),
+    };
+
+    service
+        .save_memory(&memory)
+        .context("failed to save memory")?;
+
+    Ok(MemoryResponse::from(memory))
+}

crates/zesdex-cms/src/infrastructure/http/mod.rs

@@ -0,0 +1,19 @@
+//! HTTP adapter — handler functions and DTOs for CMS REST endpoints.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod dto;
+pub mod handlers;
+
+pub use dto::{
+    ConversationResponse, MemoryCreateRequest, MemoryResponse, SettingsResponse,
+    SettingsUpdateRequest,
+};
+pub use handlers::{
+    handle_create_memory, handle_get_settings, handle_list_memories, handle_update_settings,
+};

crates/zesdex-cms/src/infrastructure/mod.rs

@@ -0,0 +1,13 @@
+//! Infrastructure layer — adapters and external concerns.
+//!
+//! Contains persistence implementations (file I/O) and HTTP handler adapters.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod http;
+pub mod persistence;

crates/zesdex-cms/src/infrastructure/persistence/app_config_repo.rs

@@ -0,0 +1,160 @@
+//! JSON file–backed `AppConfigRepository`.
+//!
+//! Path: `<base_dir>/app_config.json`
+//!
+//! On load, auto-detects Claude credentials from the environment or
+//! `~/.claude/settings.json` and merges them into the provider map.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::{Context, Result};
+use serde::{Deserialize, Serialize};
+
+use crate::domain::app_config::{AppConfig, ModelRole, ProviderConfig};
+use crate::domain::repository::AppConfigRepository;
+
+/// Persists `AppConfig` as pretty-printed JSON at `<base_dir>/app_config.json`.
+#[derive(Debug, Clone, Default)]
+pub struct JsonAppConfigRepository;
+
+impl JsonAppConfigRepository {
+    /// Create a new repository instance.
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+/// Configuration structure inside `~/.claude/settings.json`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+struct ClaudeEnv {
+    #[serde(alias = "ANTHROPIC_BASE_URL")]
+    anthropic_base_url: Option<String>,
+    #[serde(alias = "ANTHROPIC_API_KEY")]
+    anthropic_api_key: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+struct ClaudeSettings {
+    env: Option<ClaudeEnv>,
+}
+
+/// Try to read Claude credentials from `~/.claude/settings.json`'s `env` block.
+fn claude_credentials_from_file() -> Option<(String, String)> {
+    let path = dirs::home_dir()?.join(".claude").join("settings.json");
+    let content = std::fs::read_to_string(&path).ok()?;
+    let settings: ClaudeSettings = serde_json::from_str(&content).ok()?;
+    let env = settings.env?;
+    let base_url = env.anthropic_base_url?;
+    let key = env.anthropic_api_key?;
+    Some((base_url, key))
+}
+
+/// Try to read Claude credentials from environment variables.
+fn claude_credentials_from_env() -> Option<(String, String)> {
+    let base_url = std::env::var("ANTHROPIC_BASE_URL").ok()?;
+    let key = std::env::var("ANTHROPIC_API_KEY").ok()?;
+    Some((base_url, key))
+}
+
+/// Return a `ProviderConfig` for the Claude provider, checking both
+/// `~/.claude/settings.json` and the process environment.
+fn detect_claude_settings_provider() -> Option<ProviderConfig> {
+    let (base_url, key) = claude_credentials_from_file().or_else(claude_credentials_from_env)?;
+    Some(ProviderConfig {
+        api_base: base_url,
+        api_key_env: Some("ANTHROPIC_API_KEY".to_string()),
+        default_model: None,
+        default_api_key: Some(key),
+    })
+}
+
+impl AppConfigRepository for JsonAppConfigRepository {
+    fn load(&self, base_dir: &Path) -> Result<AppConfig> {
+        let path = base_dir.join("app_config.json");
+        let mut cfg: AppConfig = match std::fs::read_to_string(&path) {
+            Ok(s) => serde_json::from_str(&s)
+                .map_err(|e| anyhow::anyhow!("failed to parse app_config.json: {e}"))?,
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                tracing::info!("app_config.json not found, using defaults");
+                AppConfig::default()
+            }
+            Err(e) => {
+                return Err(anyhow::anyhow!("failed to read app_config.json: {e}"));
+            }
+        };
+
+        // Merge any default providers not present in the loaded config
+        let defaults = AppConfig::default();
+        for (name, provider) in defaults.providers {
+            cfg.providers.entry(name).or_insert(provider);
+        }
+
+        // Auto-detect Claude provider
+        if let Some(claude_provider) = detect_claude_settings_provider() {
+            cfg.providers
+                .entry("claude".to_string())
+                .or_insert(claude_provider);
+
+            let claude_models: [(&str, &str); 3] = [
+                ("claude-opus-4-8", "claude-opus-4-8"),
+                ("claude-sonnet-5", "claude-sonnet-5"),
+                ("claude-haiku-4-5", "claude-haiku-4-5-20251001"),
+            ];
+            for (role_name, model_name) in &claude_models {
+                cfg.model_roles
+                    .entry(role_name.to_string())
+                    .or_insert(ModelRole {
+                        provider: "claude".to_string(),
+                        model: model_name.to_string(),
+                        max_tokens: Some(8192),
+                        context_window: Some(200_000),
+                        temperature: Some(0.7),
+                    });
+            }
+
+            // Set as default provider only if user hasn't picked a custom default
+            if cfg.default_provider == defaults.default_provider {
+                cfg.default_provider = "claude".to_string();
+                cfg.default_model = "claude-opus-4-8".to_string();
+            }
+        }
+
+        Ok(cfg)
+    }
+
+    fn save(&self, base_dir: &Path, config: &AppConfig) -> Result<()> {
+        std::fs::create_dir_all(base_dir)
+            .with_context(|| format!("failed to create base dir '{}'", base_dir.display()))?;
+        let path = base_dir.join("app_config.json");
+        let tmp = base_dir.join("app_config.json.tmp");
+        let json = serde_json::to_string_pretty(config)
+            .context("failed to serialize app config")?;
+        {
+            let mut f = std::fs::OpenOptions::new()
+                .create(true)
+                .truncate(true)
+                .write(true)
+                .open(&tmp)
+                .with_context(|| format!("failed to write temp file '{}'", tmp.display()))?;
+            f.write_all(json.as_bytes())?;
+            f.sync_all()?;
+        }
+        std::fs::rename(&tmp, &path)
+            .with_context(|| format!("failed to rename '{}' -> '{}'", tmp.display(), path.display()))?;
+        if let Some(parent) = path.parent() {
+            if let Ok(d) = std::fs::File::open(parent) {
+                let _ = d.sync_all();
+            }
+        }
+        tracing::debug!("app_config saved to '{}'", path.display());
+        Ok(())
+    }
+}

crates/zesdex-cms/src/infrastructure/persistence/conversation_repo.rs

@@ -0,0 +1,70 @@
+//! JSON file–backed `ConversationRepository`.
+//!
+//! Path: `<session_dir>/conversation.json`
+//!
+//! Uses write-then-rename with fsync for crash safety.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::{Context, Result};
+
+use crate::domain::conversation::Conversation;
+use crate::domain::repository::ConversationRepository;
+
+/// Persists `Conversation` as pretty-printed JSON at `<session_dir>/conversation.json`.
+#[derive(Debug, Clone, Default)]
+pub struct JsonConversationRepository;
+
+impl JsonConversationRepository {
+    /// Create a new repository instance.
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl ConversationRepository for JsonConversationRepository {
+    fn load(&self, session_dir: &Path) -> Result<Conversation> {
+        let path = session_dir.join("conversation.json");
+        let data = std::fs::read_to_string(&path)
+            .with_context(|| format!("failed to read conversation at '{}'", path.display()))?;
+        let conv: Conversation = serde_json::from_str(&data)
+            .with_context(|| format!("failed to parse conversation at '{}'", path.display()))?;
+        Ok(conv)
+    }
+
+    fn save(&self, session_dir: &Path, conversation: &Conversation) -> Result<()> {
+        std::fs::create_dir_all(session_dir)
+            .with_context(|| format!("failed to create session dir '{}'", session_dir.display()))?;
+        let path = session_dir.join("conversation.json");
+        let tmp = session_dir.join("conversation.json.tmp");
+        let json = serde_json::to_string_pretty(conversation)
+            .context("failed to serialize conversation")?;
+        {
+            let mut f = std::fs::OpenOptions::new()
+                .create(true)
+                .truncate(true)
+                .write(true)
+                .open(&tmp)
+                .with_context(|| format!("failed to write temp file '{}'", tmp.display()))?;
+            f.write_all(json.as_bytes())?;
+            f.sync_all()?;
+        }
+        std::fs::rename(&tmp, &path)
+            .with_context(|| format!("failed to rename '{}' -> '{}'", tmp.display(), path.display()))?;
+        if let Some(parent) = path.parent() {
+            if let Ok(d) = std::fs::File::open(parent) {
+                let _ = d.sync_all();
+            }
+        }
+        tracing::debug!("conversation saved to '{}'", path.display());
+        Ok(())
+    }
+}

crates/zesdex-cms/src/infrastructure/persistence/edit_log_repo.rs

@@ -0,0 +1,106 @@
+//! JSONL file–backed `EditLogRepository`.
+//!
+//! Path: `<session_dir>/edits.jsonl`
+//!
+//! Append-only log: new entries are appended to the file, never rewritten.
+//! In-memory cache is capped at 10K entries to prevent unbounded growth.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::io::{BufRead, BufReader, Write};
+use std::path::Path;
+
+use anyhow::{Context, Result};
+
+use crate::domain::edit_log::{EditLog, EditLogEntry, MAX_MEMORY_ENTRIES};
+use crate::domain::repository::EditLogRepository;
+
+/// Persists `EditLog` as an append-only JSONL file at `<session_dir>/edits.jsonl`.
+#[derive(Debug, Clone, Default)]
+pub struct JsonlEditLogRepository;
+
+impl JsonlEditLogRepository {
+    /// Create a new repository instance.
+    pub fn new() -> Self {
+        Self
+    }
+
+    /// Read existing entries from disk into memory, capped at `MAX_MEMORY_ENTRIES`.
+    fn load_from_disk(path: &Path) -> Vec<EditLogEntry> {
+        let Ok(file) = std::fs::File::open(path) else {
+            return Vec::new();
+        };
+        let reader = BufReader::new(file);
+        let mut entries: Vec<EditLogEntry> = Vec::new();
+        for line in reader.lines() {
+            let Ok(line) = line else {
+                continue;
+            };
+            if let Ok(entry) = serde_json::from_str::<EditLogEntry>(&line) {
+                if entries.len() >= MAX_MEMORY_ENTRIES {
+                    entries.remove(0);
+                }
+                entries.push(entry);
+            }
+        }
+        entries
+    }
+}
+
+impl EditLogRepository for JsonlEditLogRepository {
+    fn open(&self, session_dir: &Path) -> Result<EditLog> {
+        let path = session_dir.join("edits.jsonl");
+        // Ensure parent dir exists
+        if let Some(parent) = path.parent() {
+            std::fs::create_dir_all(parent)
+                .with_context(|| format!("failed to create session dir '{}'", parent.display()))?;
+        }
+        let entries = Self::load_from_disk(&path);
+        // Touch the file if it doesn't exist yet
+        if !path.exists() {
+            std::fs::OpenOptions::new()
+                .create(true)
+                .append(true)
+                .open(&path)
+                .with_context(|| format!("failed to create edits.jsonl at '{}'", path.display()))?;
+        }
+        Ok(EditLog { entries })
+    }
+
+    fn append(&self, session_dir: &Path, log: &mut EditLog, entry: EditLogEntry) -> Result<()> {
+        let path = session_dir.join("edits.jsonl");
+        let line = serde_json::to_string(&entry)
+            .context("failed to serialize edit log entry")?
+            + "\n";
+        if let Some(parent) = path.parent() {
+            std::fs::create_dir_all(parent)
+                .with_context(|| format!("failed to create session dir '{}'", parent.display()))?;
+        }
+        {
+            let mut file = std::fs::OpenOptions::new()
+                .create(true)
+                .append(true)
+                .open(&path)
+                .with_context(|| format!("failed to open edits.jsonl at '{}'", path.display()))?;
+            file.write_all(line.as_bytes())
+                .context("failed to write edit log entry")?;
+            file.sync_all()
+                .context("failed to fsync edit log")?;
+        }
+        log.entries.push(entry);
+        // Enforce in-memory cap
+        if log.entries.len() > MAX_MEMORY_ENTRIES {
+            log.entries.remove(0);
+        }
+        Ok(())
+    }
+
+    fn entries(&self, log: &EditLog) -> Vec<EditLogEntry> {
+        log.entries.clone()
+    }
+}

crates/zesdex-cms/src/infrastructure/persistence/memory_repo.rs

@@ -0,0 +1,215 @@
+//! Markdown file–backed `MemoryRepository`.
+//!
+//! Each memory is stored as a `.md` file with YAML-ish frontmatter.
+//! Filenames are derived from the memory's `name` via slugification.
+//!
+//! Frontmatter fields parsed from `---\n...\n---\n` header:
+//! name, description, kind, created_at, updated_at, lifecycle,
+//! outcome, scope, before, after, provenances
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::collections::HashMap;
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::{Context, Result};
+
+use crate::domain::memory::Memory;
+use crate::domain::repository::MemoryRepository;
+
+/// Persists `Memory` as markdown files with YAML-ish frontmatter.
+#[derive(Debug, Clone, Default)]
+pub struct MarkdownMemoryRepository;
+
+impl MarkdownMemoryRepository {
+    /// Create a new repository instance.
+    pub fn new() -> Self {
+        Self
+    }
+
+    /// Build the frontmatter lines for a memory.
+    fn build_frontmatter(memory: &Memory) -> String {
+        let outcome_line = memory
+            .outcome
+            .as_ref()
+            .map(|o| format!("outcome: {o}\n"))
+            .unwrap_or_default();
+        let scope_line = memory
+            .scope
+            .as_ref()
+            .map(|s| format!("scope: {s}\n"))
+            .unwrap_or_default();
+        let before_line = memory
+            .before_snippet
+            .as_ref()
+            .map(|s| format!("before: {s}\n"))
+            .unwrap_or_default();
+        let after_line = memory
+            .after_snippet
+            .as_ref()
+            .map(|s| format!("after: {s}\n"))
+            .unwrap_or_default();
+        let prov_line = if memory.provenances.is_empty() {
+            String::new()
+        } else {
+            format!("provenances: {}\n", memory.provenances.join(", "))
+        };
+        format!(
+            "name: {name}\ndescription: {desc}\nkind: {kind}\n\
+             created_at: {created}\nupdated_at: {updated}\nlifecycle: {lifecycle}\n\
+             {outcome}{scope}{before}{after}{prov}",
+            name = memory.name,
+            desc = memory.description,
+            kind = memory.kind,
+            created = memory.created_at,
+            updated = memory.updated_at,
+            lifecycle = memory.lifecycle,
+            outcome = outcome_line,
+            scope = scope_line,
+            before = before_line,
+            after = after_line,
+            prov = prov_line,
+        )
+    }
+
+    /// Parse frontmatter lines into a `HashMap`.
+    fn parse_frontmatter(front: &str) -> HashMap<String, String> {
+        front
+            .lines()
+            .filter_map(|l| {
+                let mut it = l.splitn(2, ':');
+                Some((
+                    it.next()?.trim().to_string(),
+                    it.next()?.trim().to_string(),
+                ))
+            })
+            .collect()
+    }
+
+    /// Parse a memory file's contents (frontmatter + body) into a `Memory`.
+    fn parse(content: &str) -> std::io::Result<Memory> {
+        let content = content.strip_prefix("---\n").unwrap_or(content);
+        let parts: Vec<&str> = content.splitn(2, "\n---\n").collect();
+        if parts.len() < 2 {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidData,
+                "missing frontmatter",
+            ));
+        }
+        let front = Self::parse_frontmatter(parts[0]);
+        let body = parts.get(1).unwrap_or(&"").trim().to_string();
+        Ok(Memory {
+            name: front.get("name").cloned().unwrap_or_default(),
+            description: front.get("description").cloned().unwrap_or_default(),
+            content: body,
+            kind: front
+                .get("kind")
+                .cloned()
+                .unwrap_or_else(|| "reference".to_string()),
+            created_at: front
+                .get("created_at")
+                .and_then(|v| v.parse().ok())
+                .unwrap_or(0),
+            updated_at: front
+                .get("updated_at")
+                .and_then(|v| v.parse().ok())
+                .unwrap_or(0),
+            outcome: front.get("outcome").cloned().filter(|s| !s.is_empty()),
+            lifecycle: front
+                .get("lifecycle")
+                .cloned()
+                .unwrap_or_else(|| "new".to_string()),
+            scope: front.get("scope").cloned().filter(|s| !s.is_empty()),
+            before_snippet: front.get("before").cloned().filter(|s| !s.is_empty()),
+            after_snippet: front.get("after").cloned().filter(|s| !s.is_empty()),
+            provenances: front
+                .get("provenances")
+                .cloned()
+                .map(|s| {
+                    s.split(", ")
+                        .map(std::string::ToString::to_string)
+                        .collect()
+                })
+                .unwrap_or_default(),
+        })
+    }
+}
+
+impl MemoryRepository for MarkdownMemoryRepository {
+    fn list(&self, memory_dir: &Path) -> Result<Vec<String>> {
+        let Ok(entries) = std::fs::read_dir(memory_dir) else {
+            return Ok(Vec::new());
+        };
+        let slugs: Vec<String> = entries
+            .filter_map(std::result::Result::ok)
+            .filter(|e| e.path().extension().is_some_and(|x| x == "md"))
+            .filter_map(|e| {
+                let name = e.file_name().to_string_lossy().to_string();
+                // Skip special summary file
+                if name == "MEMORY.md" {
+                    return None;
+                }
+                name.strip_suffix(".md").map(std::string::ToString::to_string)
+            })
+            .collect();
+        Ok(slugs)
+    }
+
+    fn load(&self, memory_dir: &Path, name: &str) -> Result<Memory> {
+        let path = Memory::path(memory_dir, name);
+        let content = std::fs::read_to_string(&path)
+            .with_context(|| format!("failed to read memory '{name}' at '{}'", path.display()))?;
+        let memory = Self::parse(&content)
+            .map_err(|e| anyhow::anyhow!("failed to parse memory '{name}': {e}"))?;
+        Ok(memory)
+    }
+
+    fn save(&self, memory_dir: &Path, memory: &Memory) -> Result<()> {
+        let path = Memory::path(memory_dir, &memory.name);
+        let parent = path.parent().unwrap();
+        std::fs::create_dir_all(parent)
+            .with_context(|| format!("failed to create memory dir '{}'", parent.display()))?;
+
+        let frontmatter = Self::build_frontmatter(memory);
+        let content = format!("---\n{frontmatter}---\n\n{}", memory.content);
+
+        let tmp = parent.join(format!(".{}.tmp", uuid::Uuid::new_v4()));
+        {
+            let mut f = std::fs::OpenOptions::new()
+                .create(true)
+                .truncate(true)
+                .write(true)
+                .open(&tmp)
+                .with_context(|| format!("failed to write temp file '{}'", tmp.display()))?;
+            f.write_all(content.as_bytes())?;
+            f.sync_all()?;
+        }
+        std::fs::rename(&tmp, &path)
+            .with_context(|| format!("failed to rename '{}' -> '{}'", tmp.display(), path.display()))?;
+        if let Some(p) = path.parent() {
+            if let Ok(d) = std::fs::File::open(p) {
+                let _ = d.sync_all();
+            }
+        }
+        tracing::debug!("memory saved to '{}'", path.display());
+        Ok(())
+    }
+
+    fn delete(&self, memory_dir: &Path, name: &str) -> Result<()> {
+        let path = Memory::path(memory_dir, name);
+        if path.exists() {
+            std::fs::remove_file(&path)
+                .with_context(|| format!("failed to delete memory '{name}' at '{}'", path.display()))?;
+            tracing::debug!("memory deleted: '{}'", path.display());
+        } else {
+            tracing::warn!("memory '{name}' not found at '{}', skipping delete", path.display());
+        }
+        Ok(())
+    }
+}

crates/zesdex-cms/src/infrastructure/persistence/mod.rs

@@ -0,0 +1,20 @@
+//! Persistence adapters — concrete file-based repository implementations.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod app_config_repo;
+pub mod conversation_repo;
+pub mod edit_log_repo;
+pub mod memory_repo;
+pub mod settings_repo;
+
+pub use app_config_repo::JsonAppConfigRepository;
+pub use conversation_repo::JsonConversationRepository;
+pub use edit_log_repo::JsonlEditLogRepository;
+pub use memory_repo::MarkdownMemoryRepository;
+pub use settings_repo::JsonSettingsRepository;

crates/zesdex-cms/src/infrastructure/persistence/settings_repo.rs

@@ -0,0 +1,74 @@
+//! JSON file–backed `SettingsRepository`.
+//!
+//! Path: `<base_dir>/settings.json`
+//!
+//! Uses write-then-rename with fsync for crash safety.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::{Context, Result};
+
+use crate::domain::repository::SettingsRepository;
+use crate::domain::settings::Settings;
+
+/// Persists `Settings` as pretty-printed JSON at `<base_dir>/settings.json`.
+#[derive(Debug, Clone, Default)]
+pub struct JsonSettingsRepository;
+
+impl JsonSettingsRepository {
+    /// Create a new repository instance.
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl SettingsRepository for JsonSettingsRepository {
+    fn load(&self, base_dir: &Path) -> Result<Settings> {
+        let path = base_dir.join("settings.json");
+        match std::fs::read_to_string(&path) {
+            Ok(s) => serde_json::from_str(&s)
+                .map_err(|e| anyhow::anyhow!("failed to parse settings.json: {e}")),
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                tracing::info!("settings.json not found, using defaults");
+                Ok(Settings::default())
+            }
+            Err(e) => Err(anyhow::anyhow!("failed to read settings.json: {e}")),
+        }
+    }
+
+    fn save(&self, base_dir: &Path, settings: &Settings) -> Result<()> {
+        std::fs::create_dir_all(base_dir)
+            .with_context(|| format!("failed to create base dir '{}'", base_dir.display()))?;
+        let path = base_dir.join("settings.json");
+        let tmp = base_dir.join("settings.json.tmp");
+        let json = serde_json::to_string_pretty(settings)
+            .context("failed to serialize settings")?;
+        {
+            let mut f = std::fs::OpenOptions::new()
+                .create(true)
+                .truncate(true)
+                .write(true)
+                .open(&tmp)
+                .with_context(|| format!("failed to write temp file '{}'", tmp.display()))?;
+            f.write_all(json.as_bytes())?;
+            f.sync_all()?;
+        }
+        std::fs::rename(&tmp, &path)
+            .with_context(|| format!("failed to rename '{}' -> '{}'", tmp.display(), path.display()))?;
+        if let Some(parent) = path.parent() {
+            if let Ok(d) = std::fs::File::open(parent) {
+                let _ = d.sync_all();
+            }
+        }
+        tracing::debug!("settings saved to '{}'", path.display());
+        Ok(())
+    }
+}

crates/zesdex-cms/src/lib.rs

@@ -0,0 +1,17 @@
+//! `zesdex-cms` — Content Management System
+//!
+//! Clean Architecture / DDD crate layout:
+//! - **domain** — Pure entities and repository/service traits
+//! - **application** — Use-case implementations
+//! - **infrastructure** — Persistence adapters + HTTP handlers
+
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
+pub mod domain;
+pub mod application;
+pub mod infrastructure;