Adds the merged read surface (api/skill_catalog_view.py) over synced + local stores with origin discrimination and override precedence, and extends the skill MCP tools with create_skill/update_skill/delete_skill that dispatch by origin (edit local skills; create/update/remove local overrides for cloud skills). Wired into api.mcp.create_mcp_server. Full non-integration suite green (564 passed). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>