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/remember.rs

@@ -1,9 +1,12 @@
+//! Tool for saving a new memory entry to persistent project memory.
+
 use serde_json::{json, Value};
 use anyhow::{Result, anyhow};
 use super::super::Tool;
 use super::super::ToolCtx;
 use crate::model::memory::Memory;
 
+/// Tool that writes a new `Memory` entry (name/description/content/kind) to disk.
 pub struct Remember;
 
 impl Tool for Remember {
@@ -41,6 +44,16 @@ impl Tool for Remember {
         })
     }
 
+    /// Build a `Memory` from the given args and persist it to `ctx.memory_dir`.
+    ///
+    /// Flow: extract name/description/content/kind → validate name via `Memory::slugify`
+    ///       → construct `Memory` with `lifecycle: "new"` and current timestamps →
+    ///       `memory.write`.
+    ///
+    /// Why: name must slugify to a valid filename (alphanumeric + hyphens, 1-80 chars)
+    /// since it's used directly as the on-disk file identifier.
+    ///
+    /// Return: confirmation string on success; error if name is invalid or the write fails.
     fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
         let name = args.get("name")
             .and_then(|v| v.as_str())