gcontext 0.12.2

Added

• controls.yaml: single file to control the MCP surface (replaces commands.yaml, breaking)
• hidden_commands: hide slash commands by stable key
• hidden_resources: hide modules/connections from the resource picker (fnmatch globs supported)
• pinned_resources: surface specific files in the resource picker

Fixed

• Manifest loads before framework prompt registration so hidden_commands applies to built-in prompts