chore: remove goose-cli package and cleanup configuration

- Delete packages/goose-cli/ (librusty_v8 pre-built binary dependency)
- Remove global nixpkgs.config.allowUnfree from flake.nix
  (goose-cli was the only package requiring unfree binaries)
- Add .claude/ to .gitignore
- Update README.md and AGENTS.md to remove all goose-cli references

AGENTS.md

@@ -87,13 +87,7 @@ nix-overlay/
 ├── packages/
 │   ├── default/                # Meta-package listing all visible packages
 │   │   ├── default.nix
-│   │   └── package.nix
-│   ├── goose-cli/              # Example package: Goose AI agent CLI
-│   │   ├── default.nix
-│   │   ├── package.nix         # Main package definition
-│   │   ├── fetchers.nix        # Custom fetchers (if needed)
-│   │   ├── librusty_v8.nix     # V8 library pre-built binary
-│   │   └── update.py           # Update script for version bumps
+│   │    └── package.nix
 │   └── flake-inputs/           # Utility to cache all flake inputs
 │       └── default.nix
 ├── README.md                   # User-facing documentation
@@ -232,7 +226,7 @@ When adding a new package:
 
 ```bash
 # Build specific package
-nix build .#goose-cli
+nix build .#mcp-gateway
 
 # Build all packages for current system
 nix build .#packages
@@ -319,7 +313,6 @@ nix build .#<package-name>
 
 ### Package-Specific Notes
 
-- **goose-cli**: Also updates `librusty_v8` hashes automatically via the custom fetcher
 - **mcp-gateway**: Standard Rust package, `nix-update` handles version + cargoHash
 - **skillsmcp**: Pinned to a commit hash; use `--version=branch=main` or specify the target commit with `--commit`