fix: unblock resolved QA handoffs

[numnx]

What changed

• Move a task parked in QA_REVIEW_FAILED back to code-complete review state when its QA human handoff is resolved or dismissed.
• Preserve tasks that already settled through another operator action instead of regressing them.
• Make the post-budget same-session verification exception single-use, so repeated no-op continuations cannot renew the QA budget indefinitely.
• Update canonical and published QA documentation.

Root cause

Resolving a task QA escalation cleared review rows and guardrail counters but left the task in QA_REVIEW_FAILED. Status derivation intentionally preserves that human-owned state, so restarting orchestration resumed the same blocked run forever. Separately, every completed same-session continuation qualified for another post-cap verification, allowing repeated no-op continuations to push a configured review budget far beyond its limit.

Impact

Resolved QA handoffs now re-enter review as intended, while exhausted reviews stop deterministically after one final post-cap verification. Already-settled tasks remain unchanged.

Validation

• pnpm run lint
• pnpm run test:backend (399 files, 5105 passed, 7 skipped)
• pnpm run build
• Focused QA/lifecycle regression suites (131 tests passed)
• Runtime health and readiness probes passed after local restart

Risk and rollback

Risk is limited to task QA exhaustion and attention-resolution transitions. Roll back this commit to restore the prior behavior; paused sprint and task records remain durable and can be corrected through existing dashboard controls.