feat: core agent tools (fs, search, shell)

.living_spec/stories/02_core_agent_tools.md

@@ -0,0 +1,20 @@
+# Story: Core Agent Tools (The Hands)
+
+## User Story
+**As an** Agent
+**I want to** be able to read files, list directories, search content, and execute shell commands
+**So that** I can autonomously explore and modify the target project.
+
+## Acceptance Criteria
+*   [ ] Rust Backend: Implement `read_file(path)` command (scoped to project).
+*   [ ] Rust Backend: Implement `write_file(path, content)` command (scoped to project).
+*   [ ] Rust Backend: Implement `list_directory(path)` command.
+*   [ ] Rust Backend: Implement `exec_shell(command, args)` command.
+    *   [ ] Must enforce allowlist (git, cargo, npm, etc).
+    *   [ ] Must run in project root.
+*   [ ] Rust Backend: Implement `search_files(query, globs)` using `ignore` crate.
+*   [ ] Frontend: Expose these as tools to the (future) LLM interface.
+
+## Out of Scope
+*   The LLM Chat UI itself (connecting these to a visual chat window comes later).
+*   Complex git merges (simple commands only).