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/tool/memory/recall.rs

@@ -1,9 +1,12 @@
+//! Tool for reading a single memory entry or listing the whole memory index.
+
 use serde_json::{json, Value};
 use anyhow::{Result, anyhow};
 use super::super::Tool;
 use super::super::ToolCtx;
 use crate::model::memory::Memory;
 
+/// Tool that reads one memory entry by name, or lists all entries when name is omitted.
 pub struct Recall;
 
 impl Tool for Recall {
@@ -27,6 +30,12 @@ impl Tool for Recall {
         })
     }
 
+    /// Read a specific memory entry, or fall back to listing all entries.
+    ///
+    /// Flow: if `name` present and non-empty → `Memory::read` and format as frontmatter
+    ///       + body; otherwise → `list_all`.
+    ///
+    /// Return: formatted memory content, or the full index listing.
     fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
         if let Some(name) = args.get("name").and_then(|v| v.as_str()) {
             if name.is_empty() {
@@ -48,6 +57,12 @@ impl Tool for Recall {
     }
 }
 
+/// List every memory entry in `ctx.memory_dir` as a one-line summary index.
+///
+/// Flow: `Memory::list` names → for each, try `Memory::read` for kind/description →
+///       fall back to bare name if the file can't be parsed.
+///
+/// Return: `Ok` with the formatted index (never fails; missing dir yields "(no memory entries)").
 fn list_all(ctx: &ToolCtx) -> Result<String> {
     let names = Memory::list(&ctx.memory_dir);
     if names.is_empty() {