Migrate tree-sitter to WASM for cross-platform compatibility

Replace native tree-sitter with web-tree-sitter (WASM) to eliminate
native module compilation on first run. This is Phase 1 of enabling
zero-install binary distribution.

Changes:
- Remove 9 native tree-sitter packages, add web-tree-sitter
- Add tree-sitter-wasms devDep for pre-built WASM grammars
- Create wasm-loader.ts for async WASM initialization and caching
- Update languages.ts with wasmPath for each language config
- Split TS/TSX and JS/JSX into separate configs, add C language
- Add tree.delete() for proper WASM memory cleanup
- Add scripts/copy-grammars.js to bundle WASM files during build

Author: Ricoledan