Enhance tool documentation and add new features

- Added module-level documentation for memory tools (`remember`, `recall`, `forget`) to clarify their purpose.
- Improved documentation in `recall.rs` and `remember.rs` to describe the functionality and flow of memory entry operations.
- Updated `mod.rs` to include descriptions for the tool trait and execution context.
- Enhanced `plan.rs` with detailed comments on plan-mode signaling tools.
- Documented text search tools in `search.rs` to explain their functionality.
- Improved sequential-thinking tool documentation in `seqthink.rs`.
- Added safety filter documentation in `shell_filter` for credential and git operations.
- Enhanced utility tools documentation, including `cd`, `dir_cache_update`, and `todowrite`.
- Improved rendering documentation in view modules (`chat`, `markdown`, `status`, `workflow`) to clarify rendering flows and purposes.

src/app/state/snapshot.rs

@@ -1,11 +1,16 @@
+//! Opaque, serializable snapshot of application state used for
+//! attach/daemon IPC transfer.
+
 use serde::{Deserialize, Serialize};
 
+/// A JSON-boxed snapshot of app state, opaque to the transport layer.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct StateSnapshot {
     pub snapshot: serde_json::Value,
 }
 
 impl StateSnapshot {
+    /// Create an empty snapshot (`{}`).
     pub fn new() -> Self {
         StateSnapshot {
             snapshot: serde_json::json!({}),
@@ -13,10 +18,16 @@ impl StateSnapshot {
     }
 }
 
+/// Serialize a snapshot to bytes for transport over the daemon socket.
+///
+/// Return: JSON-encoded bytes, or a serde error.
 pub fn serialize_snapshot(snapshot: &StateSnapshot) -> anyhow::Result<Vec<u8>> {
     Ok(serde_json::to_vec(snapshot)?)
 }
 
+/// Parse a snapshot previously produced by `serialize_snapshot`.
+///
+/// Return: the decoded `StateSnapshot`, or a serde error.
 pub fn deserialize_snapshot(data: &[u8]) -> anyhow::Result<StateSnapshot> {
     Ok(serde_json::from_slice(data)?)
 }