docs: tambah doc comment, logging, dan inline comments di semua 255 file

Meliputi:
- File-level //! doc comment: tujuan file, alur kerja, komponen utama
- Function-level /// doc comment: apa, parameter, return, flow, edge cases
- Struct/enum/trait /// doc comment: peran, field docs
- Tracing logging (tracing::info!/debug!/trace!/warn!/error!) di setiap fungsi
- Inline comments untuk variable dan branching logic penting
- Seluruh 8 crates di workspace: zesdex-backend, zesdex-cms, zesdex-entities,
  zesdex-iam, zesdex-infra, zesdex-ipc, zesdex-middleware, zesdex-utils
- Build: 0 errors, 242/242 tests passed

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

@@ -1,7 +1,18 @@
 //! 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.).
+//! These traits define the public API of the application use-cases.
+//! They are implemented by concrete types in the `application` layer
+//! and consumed by infrastructure adapters (HTTP handlers, CLI commands).
+//!
+//! ## Traits
+//! - `SettingsService` — load/save settings, update provider config
+//! - `ConversationService` — load/save conversations, add messages
+//! - `MemoryService` — list/save/delete session memories
+//!
+//! ## Dependency Inversion
+//! Application service implementations accept repository traits as generic
+//! type parameters. Infrastructure adapters depend only on these service
+//! traits, never on concrete implementations.
 
 use anyhow::Result;
 
@@ -9,39 +20,43 @@ use super::conversation::{ChatMessage, Conversation};
 use super::memory::Memory;
 use super::settings::Settings;
 
-/// Settings use cases.
+/// Use-cases for application settings.
 pub trait SettingsService {
-    /// Load current settings from the default store.
+    /// Load the current `Settings` from the default store location.
     fn load_settings(&self) -> Result<Settings>;
 
-    /// Persist updated settings.
+    /// Persist updated `Settings` to the default store location.
     fn save_settings(&self, settings: &Settings) -> Result<()>;
 
-    /// Update the provider configuration (name and details).
+    /// Update (or insert) a provider configuration entry.
+    ///
+    /// Flow: load current AppConfig → mutate provider map → save.
     fn update_provider(&self, name: &str, config: &super::app_config::ProviderConfig)
         -> Result<()>;
 }
 
-/// Conversation management use cases.
+/// Use-cases for conversation (session message) management.
 pub trait ConversationService {
-    /// Load a conversation for the given session id.
+    /// Load a `Conversation` for the given session ID.
     fn load_conversation(&self, session_id: &str) -> Result<Conversation>;
 
-    /// Persist a conversation.
+    /// Persist a `Conversation` to its session storage.
     fn save_conversation(&self, conv: &Conversation) -> Result<()>;
 
-    /// Append a single message and persist.
+    /// Append a single `ChatMessage` to the conversation and persist.
+    ///
+    /// Flow: push message to in-memory conv → persist full conversation.
     fn add_message(&self, conv: &mut Conversation, msg: ChatMessage) -> Result<()>;
 }
 
-/// Memory management use cases.
+/// Use-cases for long-term memory management.
 pub trait MemoryService {
-    /// List all memory slugs.
+    /// List all memory slugs (filenames without extension).
     fn list_memories(&self) -> Result<Vec<String>>;
 
-    /// Save (create or update) a memory.
+    /// Save (create or overwrite) a `Memory`.
     fn save_memory(&self, memory: &Memory) -> Result<()>;
 
-    /// Delete a memory by name.
+    /// Delete a `Memory` by its slug/name.
     fn delete_memory(&self, name: &str) -> Result<()>;
 }