# Specification: Interactive AST Tree Masking

## Overview
Transform the Context Panel by allowing users to inspect the AST of C/C++ files and selectively mask individual symbols (classes, methods, functions). Instead of treating a file as a single unit, users can define an `ASTMask` to expose only what is relevant.

## Acceptance Criteria
- [ ] An `[Inspect]` button in the Context Panel opens an AST Outline window for the selected file.
- [ ] The Outline window renders a hierarchical tree of symbols using `tree-sitter`.
- [ ] Users can toggle individual nodes as `[Def]` (Definition), `[Sig]` (Signature), or `[Hide]`.
- [ ] `FileItem` model is updated to persist this `ASTMask` dictionary.
- [ ] `aggregate.py` dynamically stitches the file content based on the `ASTMask`, automatically resolving line numbers by symbol name to survive agent modifications.
