fix: remove conflicting tree-sitter-go and tree-sitter-python dependencies

These grammars require tree-sitter@^0.25.0 but we use 0.21.1.
They already failed at runtime with try/catch graceful fallback.
Removing them fixes npm peer dependency conflict during pi install.

- Remove tree-sitter-go and tree-sitter-python from dependencies
- ast-extract.ts already handles missing grammars gracefully
- Heuristics + LLM layer cover Go/Python analysis anyway

.gitignore

@@ -5,3 +5,5 @@ coverage/
 .DS_Store
 .env
 .pi-map.md
+# Local Pi runtime state
+.atl/