docs: add TODO items for large file handling and nixpkgs-packages MCP

- Add file size metadata to get_option declarations
- Add range parameters to get_file with sensible defaults
- New MCP server idea for indexing nixpkgs packages

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

TODO.md

@@ -4,12 +4,18 @@
 
 - [ ] Progress reporting during indexing ("Fetching nixpkgs... Parsing options... Indexing files...")
 - [ ] Add `search_files` MCP tool - search for files by path pattern (e.g., find all nginx-related modules)
+- [ ] Include file size metadata in `get_option` declarations (byte size and/or line count) so clients know file sizes before fetching
+- [ ] Add range parameters to `get_file` (`offset`, `limit`) with sensible defaults (~200-300 lines) to avoid dumping massive files
 
 ## Robustness
 
 - [ ] PostgreSQL integration tests with testcontainers (currently skipped without manual DB setup)
 - [ ] Graceful handling of concurrent indexing (what happens if two clients index the same revision?)
 
+## New MCP Servers
+
+- [ ] `nixpkgs-packages` - Index and search nixpkgs packages (similar architecture to nixos-options, but for packages instead of options)
+
 ## Nice to Have
 
 - [ ] Option history/diff - compare options between two revisions ("what changed in services.nginx between 24.05 and 24.11?")