feat: derive author from PR, remove from manifests, and improve validation

[wzlng]

No description provided.

[github-actions]

Validation passed

> brv-hub@1.0.0 validate
> node scripts/validate-manifest.js && node scripts/validate-structure.js

✅ Valid: ByteRover Ship & Handoff v1.0.0 (skills/byterover-ship/manifest.json)
✅ Valid: ByteRover Code Review v1.0.0 (skills/byterover-review/manifest.json)
✅ Valid: ByteRover Project Progress v1.0.0 (skills/byterover-progress/manifest.json)
✅ Valid: ByteRover Context-Aware Planning v1.0.0 (skills/byterover-plan/manifest.json)
✅ Valid: ByteRover Project Onboarding v1.0.0 (skills/byterover-onboard/manifest.json)
✅ Valid: ByteRover Milestone Planning v1.0.0 (skills/byterover-milestone/manifest.json)
✅ Valid: ByteRover Explore v1.0.0 (skills/byterover-explore/manifest.json)
✅ Valid: ByteRover Phase Execution v1.0.0 (skills/byterover-execute/manifest.json)
✅ Valid: ByteRover Systematic Debugging v1.0.0 (skills/byterover-debug/manifest.json)
✅ Valid: ByteRover Knowledge Audit v1.0.0 (skills/byterover-audit/manifest.json)
✅ Valid: TypeScript Kickstart v1.0.0 (bundles/typescript-kickstart/manifest.json)

✅ All 11 manifests are valid.
✅ Structure OK: byterover-ship (agent-skill → skills/)
✅ Structure OK: byterover-review (agent-skill → skills/)
✅ Structure OK: byterover-progress (agent-skill → skills/)
✅ Structure OK: byterover-plan (agent-skill → skills/)
✅ Structure OK: byterover-onboard (agent-skill → skills/)
✅ Structure OK: byterover-milestone (agent-skill → skills/)
✅ Structure OK: byterover-explore (agent-skill → skills/)
✅ Structure OK: byterover-execute (agent-skill → skills/)
✅ Structure OK: byterover-debug (agent-skill → skills/)
✅ Structure OK: byterover-audit (agent-skill → skills/)
✅ Structure OK: typescript-kickstart (bundle → bundles/)

✅ All 11 entries have valid structure.

[github-actions]

Validation passed

> brv-hub@1.0.0 validate
> node scripts/validate-manifest.js && node scripts/validate-structure.js

✅ Valid: ByteRover Ship & Handoff v1.0.0 (skills/byterover-ship/manifest.json)
✅ Valid: ByteRover Code Review v1.0.0 (skills/byterover-review/manifest.json)
✅ Valid: ByteRover Project Progress v1.0.0 (skills/byterover-progress/manifest.json)
✅ Valid: ByteRover Context-Aware Planning v1.0.0 (skills/byterover-plan/manifest.json)
✅ Valid: ByteRover Project Onboarding v1.0.0 (skills/byterover-onboard/manifest.json)
✅ Valid: ByteRover Milestone Planning v1.0.0 (skills/byterover-milestone/manifest.json)
✅ Valid: ByteRover Explore v1.0.0 (skills/byterover-explore/manifest.json)
✅ Valid: ByteRover Phase Execution v1.0.0 (skills/byterover-execute/manifest.json)
✅ Valid: ByteRover Systematic Debugging v1.0.0 (skills/byterover-debug/manifest.json)
✅ Valid: ByteRover Knowledge Audit v1.0.0 (skills/byterover-audit/manifest.json)
✅ Valid: TypeScript Kickstart v1.0.0 (bundles/typescript-kickstart/manifest.json)

✅ All 11 manifests are valid.
✅ Structure OK: byterover-ship (agent-skill → skills/)
✅ Structure OK: byterover-review (agent-skill → skills/)
✅ Structure OK: byterover-progress (agent-skill → skills/)
✅ Structure OK: byterover-plan (agent-skill → skills/)
✅ Structure OK: byterover-onboard (agent-skill → skills/)
✅ Structure OK: byterover-milestone (agent-skill → skills/)
✅ Structure OK: byterover-explore (agent-skill → skills/)
✅ Structure OK: byterover-execute (agent-skill → skills/)
✅ Structure OK: byterover-debug (agent-skill → skills/)
✅ Structure OK: byterover-audit (agent-skill → skills/)
✅ Structure OK: typescript-kickstart (bundle → bundles/)

✅ All 11 entries have valid structure.