MVP 1: Executor GO/NO-GO gate

Add a pre-execution gate where the executor model (Sonnet/Haiku) evaluates the task spec before starting work.

The gate prompt: 1. Ask the executor to restate the task in its own words 2. Ask: 'Can you implement this without asking clarifying questions? If YES: GO. If NO: list every question you need answered.' 3. If GO → proceed to execution as normal 4. If NO-GO → bounce the task back with status change (e.g. back to Open with a comment containing the questions)

Implementation location: this should happen in the orchestrator/coder workflow, after task claim but before the coder starts working. Likely in Omni/Ide/ORCHESTRATOR.md workflow or the agentd spawn logic.

Key design decisions:

• The restatement step catches 'confident ignorance' — executor thinks it understands but restates incorrectly
• On NO-GO, the task gets a comment with the executor's questions and returns to Open for human review
• Track: gate pass rate, question categories, correlation between NO-GO and eventual task failure

Acceptance criteria:

• Every task goes through the gate before the coder starts
• GO tasks proceed normally (no added latency beyond 1 LLM call)
• NO-GO tasks are bounced back with executor's questions as a comment
• Gate results (GO/NO-GO, restatement, questions) are logged on the task