feat: add memory management tools and utility commands

src/tool/utility/todowrite.rs

@@ -0,0 +1,54 @@
+use std::fs;
+use std::path::PathBuf;
+use serde_json::{json, Value};
+use anyhow::{Result, anyhow};
+use super::super::Tool;
+use super::super::ToolCtx;
+
+pub struct Todowrite;
+
+impl Tool for Todowrite {
+    fn name(&self) -> &'static str {
+        "todowrite"
+    }
+
+    fn description(&self) -> &'static str {
+        "Append a task to the session todo list. The todo persists in the session directory and is visible in the Todo panel."
+    }
+
+    fn parameters(&self) -> Value {
+        json!({
+            "type": "object",
+            "properties": {
+                "task": {
+                    "type": "string",
+                    "description": "Task description to add"
+                }
+            },
+            "required": ["task"]
+        })
+    }
+
+    fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
+        let task = args.get("task")
+            .and_then(|v| v.as_str())
+            .ok_or_else(|| anyhow!("missing required argument: task"))?;
+
+        let path: PathBuf = ctx.session_dir.join("todo.md");
+        let now = chrono::Utc::now();
+        let timestamp = now.format("%Y-%m-%d %H:%M:%S");
+        let line = format!("- [ ] {} ({})\n", task, timestamp);
+
+        fs::OpenOptions::new()
+            .create(true)
+            .append(true)
+            .open(&path)
+            .map_err(|e| anyhow!("failed to open todo.md: {}", e))?
+            .write_all(line.as_bytes())
+            .map_err(|e| anyhow!("failed to write to todo.md: {}", e))?;
+
+        Ok(format!("added task to todo.md: {}", task))
+    }
+}
+
+use std::io::Write;