Add plugin manifest discovery model

[almogdepaz]

Summary

• add plugin manifest schema/discovery surfaces
• add docs, UI/API/CLI wiring, and tests

Source plan: .plans/g-plugin-manifest-model.md

Verification

• cherry-picked Ralph task commit onto fresh branch from main

[almogdepaz]

ran review passes against main...pr/herdr-g-plugin-manifest-model:

• edc-review security/adversarial
• edc-delivery-review goal + architecture fit
• edc-audit quality/maintainability
• antipattern-scan changed-region smell pass

verdict

• security: no direct code-execution path found; manifests are data-only and not executed.
• delivery/architecture: delivered for v1 discovery/listing/validation.
• quality/antipatterns: acceptable, with one rollout caveat.

notes

• manifest discovery rejects symlink traversal, caps file size, validates unknown fields, and labels trust/source.
• UI rendering escapes plugin fields and only summarizes capabilities.
• CLI/API expose listing and validation without executing plugin-declared commands/actions.

advisory

• where: docs/plugin-manifests.md:4-10, src/cli/config.ts:31-45, src/server/routes.ts:436-446
• issue: docs mention configured pluginDirs, but do not show the ~/.wolfpack/config.json shape or WOLFPACK_PLUGIN_DIRS env option that the implementation reads.
• recommendation: add a tiny config example so users can actually exercise non-default plugin roots without reading source.

recommendation

approve after/with the docs tweak.

[almogdepaz]

addressed the review advisory in 7ac6742.\n\nwhat changed:\n- added docs for ~/.wolfpack/config.json pluginDirs\n- added docs for WOLFPACK_PLUGIN_DIRS colon-separated roots\n- added a docs regression assertion\n\nverification:\n- bun test tests/unit/plugin-manifest.test.ts\n- bun test\n- bun run typecheck\n\nreview status: finding was valid; fixed.