Three-tier module selection: official, community (category drill-down
with featured/search), and custom GitHub URL.
- Add RegistryClient shared fetch utility
- Add CommunityModuleManager with SHA-pinned cloning (refuses install
if approved SHA cannot be reached; uses HEAD when no SHA set)
- Add CustomModuleManager for arbitrary GitHub repo installation
- Extend findModuleSource chain with community and custom fallthrough
- Extend manifest to detect community and custom source types
- Add Config.customModulesMeta for custom module metadata
Brian Madison