test(behaviour): add review dispatch trigger scenarios (bash routing)

[ifireball]

What is missing

Behaviour tests cover triage dispatch triggers partially, but review has no behaviour scenarios that verify dispatch triggers fire the correct agent run on the current bash router in reusable-dispatch.yml.

We need this baseline before porting review's trigger logic to harness CEL expressions.

What should happen

One vertical PR adds Godog scenarios for review dispatch triggers:

• Triggers: PR opened/synchronize, ready-for-review label, /fs-review
• Uses bash route job only (no CEL, no harness-dispatch)
• Agent runs via dummy runtime; assert outcome (e.g. behaviour-results.json or expected side effect)
• Requires behaviour framework (PR #1982)

Merge criterion

make behaviour-test green with new review trigger scenarios.

Blocks

Port review to harness CEL trigger (#2898).

Related

Part of epic #2888. Does not block the custom-agent harness-dispatch issue (#2889).

[fullsend-ai-triage]

🤖 Triage · ⚠️ Cancelled · Started 8:33 AM UTC · Ended 8:34 AM UTC
Commit: 9f4f2b6 · View workflow run →

[fullsend-ai-triage]

🤖 Finished Triage · ✅ Success · Started 8:35 AM UTC · Completed 8:37 AM UTC
Commit: 9f4f2b6 · View workflow run →