Refactor subagent and workflow domain models; migrate access tiers and events to domain module

- Moved `AccessTier` and `SubagentEvent` enums to `zesdex_domain::subagent`.
- Consolidated workflow-related types into `zesdex_domain::workflow`.
- Updated references across the codebase to use the new domain models.
- Refactored tool execution logic to utilize a new `ToolExecutor` trait.
- Enhanced `AgentTurnService` to handle tool calls and events more effectively.
- Adjusted API handlers and state management to align with new domain structure.

apps/domain/src/agent/mod.rs

@@ -0,0 +1,242 @@
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+use crate::core::{ChatMessage, ToolCallResult, UsageStats};
+
+/// Which kind of caller (main agent vs. subagent vs. reviewer) is
+/// invoking a tool, used to scope permissions and tag log/output paths.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Hash)]
+pub enum Origin {
+    /// The main agent turn loop.
+    Main,
+    /// A spawned subagent (test-gen, arch-review, security-review, etc.).
+    SubAgent,
+    /// The auto-inline review step after an edit.
+    Reviewer,
+}
+
+impl Origin {
+    /// Short string tag for this origin, used in filenames and logs.
+    pub fn tag(self) -> String {
+        match self {
+            Origin::Main => "main",
+            Origin::SubAgent => "subagent",
+            Origin::Reviewer => "reviewer",
+        }
+        .to_string()
+    }
+}
+
+/// Severity/category of a toast notification, used to pick its color.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ToastKind {
+    Info,
+    Success,
+    Warning,
+    Error,
+    Lesson,
+}
+
+/// A transient status message shown in the TUI, auto-dismissed after `lifetime_ms`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Toast {
+    pub kind: ToastKind,
+    pub message: String,
+    pub created_at: i64,
+    pub lifetime_ms: u64,
+}
+
+impl Toast {
+    /// Create a toast with a default 5-second lifetime, stamped with now.
+    pub fn new(kind: ToastKind, message: String) -> Self {
+        Toast {
+            kind,
+            message,
+            created_at: chrono::Utc::now().timestamp_millis(),
+            lifetime_ms: 5000,
+        }
+    }
+
+    /// Whether this toast's lifetime has elapsed as of `now_ms`.
+    pub fn expired(&self, now_ms: i64) -> bool {
+        let lifetime = self.lifetime_ms as i64;
+        now_ms - self.created_at > lifetime
+    }
+}
+
+/// Agent status for workflow engine progress tracking.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub enum AgentStatus {
+    Pending,
+    Running,
+    Completed,
+    Failed(String),
+    Cancelled,
+}
+
+impl std::fmt::Display for AgentStatus {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            AgentStatus::Pending => write!(f, "pending"),
+            AgentStatus::Running => write!(f, "running"),
+            AgentStatus::Completed => write!(f, "completed"),
+            AgentStatus::Failed(msg) => write!(f, "failed: {msg}"),
+            AgentStatus::Cancelled => write!(f, "cancelled"),
+        }
+    }
+}
+
+/// Events emitted onto the turn-event queue while an agent turn runs,
+/// consumed by the event loop to update state and drive re-renders.
+#[derive(Debug, Clone)]
+pub enum TurnEvent {
+    AssistantMessage(ChatMessage),
+    ToolResult {
+        tool_call_id: String,
+        tool_name: String,
+        output: String,
+        is_error: bool,
+        path: Option<String>,
+    },
+    SystemNote {
+        kind: String,
+        message: String,
+    },
+    StreamStart,
+    StreamToken(String),
+    StreamReasoning(String),
+    StreamDone(ChatMessage),
+    Usage {
+        tokens_in: u64,
+        tokens_out: u64,
+    },
+    ReviewUsage {
+        tokens_in: u64,
+        tokens_out: u64,
+    },
+    Compacted(Vec<ChatMessage>),
+    Error(String),
+    Done,
+    WorkflowAgentUpdate {
+        agent_id: String,
+        agent_name: String,
+        status: AgentStatus,
+    },
+    TodoUpdate(String),
+    PlanUpdate(String),
+}
+
+/// How a pending tool call should be executed when the turn resumes.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ExecutionModel {
+    Inline,
+    Deferred,
+    AsyncTokio,
+}
+
+/// A tool call awaiting execution, along with which execution model
+/// (inline, deferred, async) it should run under.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PendingTool {
+    pub tool_name: String,
+    pub args: serde_json::Value,
+    pub execution_model: ExecutionModel,
+}
+
+/// Reference to a background bash job tracked in session state.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct BashJobRef {
+    pub id: String,
+    pub command: String,
+    pub started_at: i64,
+    pub running: bool,
+}
+
+/// Per-session runtime state: message history, pending tool queue,
+/// background bash jobs, lesson/review counters.
+#[derive(Debug, Clone)]
+pub struct SessionRuntime {
+    pub messages: Vec<ChatMessage>,
+    pub tool_call_results: Vec<ToolCallResult>,
+    pub pending_tool_queue: Vec<PendingTool>,
+    pub bash_jobs: Vec<BashJobRef>,
+    pub subagent_queue: usize,
+    pub edit_count: u32,
+    pub consecutive_empty_reviews: u32,
+    pub session_start: i64,
+    pub lesson_count: u32,
+    pub lessons_user: u32,
+    pub lessons_feedback: u32,
+    pub lessons_project: u32,
+    pub lessons_reference: u32,
+    pub lessons_active: u32,
+    pub lessons_stale: u32,
+    pub lessons_contradicted: u32,
+    pub lessons_human: u32,
+    pub lessons_verified: u32,
+    pub lessons_unverified: u32,
+    pub review_count: u32,
+    pub session_dir: PathBuf,
+    pub usage: UsageStats,
+    pub hive_mind_converged: bool,
+}
+
+impl SessionRuntime {
+    pub fn new(session_dir: PathBuf) -> Self {
+        SessionRuntime {
+            messages: Vec::new(),
+            tool_call_results: Vec::new(),
+            pending_tool_queue: Vec::new(),
+            bash_jobs: Vec::new(),
+            subagent_queue: 0,
+            edit_count: 0,
+            consecutive_empty_reviews: 0,
+            session_start: chrono::Utc::now().timestamp_millis(),
+            lesson_count: 0,
+            lessons_user: 0,
+            lessons_feedback: 0,
+            lessons_project: 0,
+            lessons_reference: 0,
+            lessons_active: 0,
+            lessons_stale: 0,
+            lessons_contradicted: 0,
+            lessons_human: 0,
+            lessons_verified: 0,
+            lessons_unverified: 0,
+            review_count: 0,
+            session_dir,
+            usage: UsageStats::default(),
+            hive_mind_converged: false,
+        }
+    }
+
+    pub fn push_message(&mut self, msg: ChatMessage) {
+        self.messages.push(msg);
+    }
+}
+
+/// Simple ASCII progress display for a long-running operation.
+#[derive(Debug, Clone)]
+pub struct ProgressState {
+    pub current: u64,
+    pub total: u64,
+    pub message: String,
+    pub start_time: i64,
+}
+
+use std::collections::VecDeque;
+use std::sync::atomic::AtomicBool;
+use std::sync::{Arc, Mutex};
+
+/// Owned parameters required to spawn and execute an agent turn.
+pub struct AgentTurnParams {
+    pub messages: Vec<ChatMessage>,
+    pub session_dir: PathBuf,
+    pub workspace_roots: Vec<PathBuf>,
+    pub turn_events: Arc<Mutex<VecDeque<TurnEvent>>>,
+    pub in_flight: Arc<AtomicBool>,
+    pub abort: Arc<AtomicBool>,
+    pub api_key: String,
+    pub model: String,
+    pub api_base: Option<String>,
+}

apps/domain/src/lib.rs

@@ -28,6 +28,9 @@ pub mod auth;
 pub mod cms;
 pub mod core;
 pub mod error;
+pub mod agent;
+pub mod workflow;
+pub mod subagent;
 
 // Re-export all public items from each module for ergonomic imports.
 // Consumers can do `use zesdex_domain::*` for common types.
@@ -50,3 +53,6 @@ pub use core::{
     ToolCallResult, ToolDef, ToolFunction, ToolFunctionDef, UsageStats,
 };
 pub use error::DomainError;
+pub use agent::*;
+pub use workflow::*;
+pub use subagent::*;

apps/domain/src/subagent/mod.rs

@@ -0,0 +1,41 @@
+//! Subagent domain models.
+
+/// Events emitted by a running subagent.
+#[derive(Debug, Clone)]
+pub enum SubagentEvent {
+    Started {
+        agent_id: String,
+        directive: String,
+    },
+    ToolCall {
+        agent_id: String,
+        tool_name: String,
+    },
+    ToolResult {
+        agent_id: String,
+        tool_name: String,
+        output: String,
+    },
+    Completed {
+        agent_id: String,
+        output: String,
+    },
+    Failed {
+        agent_id: String,
+        error: String,
+    },
+}
+
+/// Access tier for subagent tool permissions.
+///
+/// Tiers are cumulative: `Write` includes everything in `Read`, and `Full`
+/// includes everything in `Write`.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AccessTier {
+    /// Read-only: search, read, glob, utility tools (no mutations).
+    Read,
+    /// Read + Write: above plus write, edit, delete, git, memory.
+    Write,
+    /// Full: above plus bash, shell, LSP, workflow, plan tools.
+    Full,
+}

apps/domain/src/workflow/mod.rs

@@ -0,0 +1,45 @@
+//! Workflow and Hive-mind domain models.
+
+/// A single phase in a parsed workflow script.
+#[derive(Debug, Clone)]
+pub struct WorkflowPhase {
+    pub name: String,
+    pub directive: String,
+}
+
+/// A parsed workflow script with named phases.
+#[derive(Debug, Clone)]
+pub struct WorkflowScript {
+    pub name: String,
+    pub phases: Vec<WorkflowPhase>,
+}
+
+/// A directive for a single processing node in the hive mind.
+#[derive(Debug, Clone)]
+pub struct NodeDirective {
+    pub directive: String,
+    pub access_tier: String,
+}
+
+/// A cognitive cycle plan — ordered list of cycles, each containing
+/// parallel node directives.
+#[derive(Debug, Clone)]
+pub struct CognitiveCyclePlan {
+    pub cycles: Vec<Vec<NodeDirective>>,
+}
+
+/// A single cycle in a cognitive cycle plan — parallel node directives
+/// executed together.
+#[derive(Debug, Clone)]
+pub struct CognitiveCycle {
+    pub index: u32,
+    pub directives: Vec<NodeDirective>,
+}
+
+/// Output from a single hive-mind processing node after a cycle completes.
+#[derive(Debug, Clone)]
+pub struct NodeOutput {
+    pub id: String,
+    pub directive: String,
+    pub output: String,
+}