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/fs/delete.rs

@@ -1,3 +1,5 @@
+//! Tool: `delete` — remove a file or empty directory relative to a workspace root.
+
 use std::fs;
 use std::path::PathBuf;
 use serde_json::{json, Value};
@@ -7,6 +9,7 @@ use super::super::ToolCtx;
 use super::super::resolve_path;
 use super::helpers::arg_str;
 
+/// Tool: delete a file or empty directory. Refuses non-empty directories.
 pub struct Delete;
 
 impl Tool for Delete {
@@ -31,6 +34,10 @@ impl Tool for Delete {
         })
     }
 
+    /// Delete a file or empty directory. Returns success message or errors on failure.
+    ///
+    /// Flow: resolve path → check existence → check dir/file → remove.
+    /// Only empty directories are deletable (non-empty returns an error).
     fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
         let rel = arg_str(args, "path")?;
         let path: PathBuf = resolve_path(&ctx.workspaces, &rel)?;