Add static native module registry

[IgorWarzocha]

Goal

Add a small static registry for built-in native capability modules so terminal, GitOps, and future native surfaces have one discoverable place to declare their identity before any real plugin system exists.

Scope

• Define a lightweight native module contract with metadata only at first: id, label, description, and optional capability tags.
• Add a static registry under the app/native area that registers existing built-in modules such as nativeTerminalModule and nativeGitOpsModule.
• Keep every module always enabled; no user config, dynamic loading, external plugins, lifecycle hooks, permissions, or marketplace behavior in this issue.
• Document the difference between native capability modules and core app modules so future aliases do not drift.

Acceptance criteria

• Existing native modules are registered in one typed static registry.
• The registry can be imported without side effects or UI/runtime behavior changes.
• Native module metadata is easy to inspect from tests or developer tooling.
• The issue does not introduce plugin enable/disable behavior yet.
• bun run ai:check passes.

Notes

This is the bridge after the module-boundary work. It should make future contribution slots easier, but the first slice should stay deliberately boring and metadata-only.