t163: Prevent false task completion cascade (AGENTS.md rule + issue-sync guard + supervisor verify)

[github-actions]

Task ID: t163 | Estimate: ~4h (ai:2h test:1h read:1h) | Logged: 2026-02-08
Tags: plan quality workflow

Subtasks

• t163.1 Add task completion rules to AGENTS.md Planning & Tasks section ~15m blocked-by:none
• t163.2 Add guard to issue-sync-helper.sh cmd_close() - require merged PR or verified: field ~1h blocked-by:none
• t163.3 Add pre-commit validation for TODO.md [x] transitions ~1h blocked-by:none
• t163.4 Add supervisor verify phase after worker PR merge ~1.5h blocked-by:none

Notes

Rule: NEVER mark [x] unless YOU wrote code/content in THIS session. Workers leave tasks for reviewer. Verify deliverable exists and is substantive before marking.
cmd_close currently blindly closes issues when TODO.md has [x]. Add check: task must have either a merged PR ref or verified:YYYY-MM-DD field. Dry-run by default, --force for real close.
Git hook or CI check: when task goes [ ] -> [x], verify current branch has commits touching related files. Warn if no deliverable found.
After merge, supervisor checks: file exists, not empty, ShellCheck pass for .sh, word count > threshold for .md. Only after verify -> [x] + issue close.

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Synced from TODO.md by issue-sync-helper.sh