[M0-S11] Board automation: project sync, PR conventions, roll-up, /take #79

Problem

Cards should move by themselves: draft PR → In progress, ready → In review, merge → Done, and epics flag when their last story closes. Native project workflows cover part of it; the rest needs workflows.

Acceptance criteria

• project-sync.yml (+ .github/project-config.json): PR draft/ready/closed states, linked-issue status, start and completed dates, daily repair
• pr-conventions.yml: Conventional title (incl. art), a linked issue, author assigned, path labels
• sub-issue-rollup.yml: ready-for-acceptance on the epic when the last sub-issue closes; never closes the epic
• issue-commands.yml: /take and /drop
• Workflows run trusted default-branch code only; a missing PROJECTS_TOKEN fails visibly
• Script checks run in CI

Notes and dependencies

Model: Room Finder .github/scripts/. Needs the PROJECTS_TOKEN secret (fine-grained token, THD-AI Projects read/write). Stack layer 3 of 3. Suggested owner: Alexander (pipeline, art, scenes, deploy).

Verification

Script checks pass; after merge: a draft PR moves its issue to In progress, ready → In review, merge → Done.