Integrate SkillSource into ai:sync-kb Pipeline

Context Following the implementation of SkillSource.mjs (Epic #11317), the source needs to be wired into the main Knowledge Base synchronization pipeline.

The Problem The SkillSource currently exists but is not invoked during npm run ai:sync-kb, leaving the Knowledge Base unpopulated with skill chunks.

The Architectural Reality The DatabaseService.mjs or sync.mjs orchestrates the different sources. We must add SkillSource to the list of active extractors.

The Fix Integrate SkillSource into the main extraction loop. Ensure the sync properly handles the type: 'skill' chunks and updates the vector database accordingly.

Acceptance Criteria

• Import and instantiate SkillSource in the Knowledge Base sync orchestrator.
• Add SkillSource to the active sources list.
• Verify that running npm run ai:sync-kb successfully embeds skill markdown files into ChromaDB.

Origin Session ID: 2c4aa4df-2628-45ae-a9c2-156fd9308f21