forge:retry at review_response_gate creates infinite pause loop — contested_comments never cleared

[ekuris-redhat]

When a workflow is stuck at review_response_gate and a user adds the forge:retry label, the workflow unpauses but immediately re-pauses in an infinite loop. This is because the retry handler does not clear contested_comments from the state.

Related: This issue compounds #184 — since review_response_gate cannot be unpaused via GitHub PR review events, forge:retry is the only alternative, but it doesn't work either.

Steps to reproduce

1. Submit a PR review with changes requested
2. Forge analyzes the review, finds contested comments, posts objections on the PR
3. Workflow pauses at review_response_gate
4. Add forge:retry label on the Jira ticket

Expected behavior

The workflow should unpause, clear the contested state, and return to human_review_gate to accept new review input.

Actual behavior

The retry handler unpauses the workflow, but:

1. review_response_gate is re-invoked and immediately sets is_paused=True again (line 30-34 of implement_review.py)
2. route_review_response checks is_paused first and returns END — the routing logic that would advance the workflow is never reached
3. The workflow is stuck again at the same gate

Worker logs show the loop:

Detected retry signal via forge:retry label for review_response_gate
Retry requested for AISOS-XXXX at review_response_gate (clearing error: none)
Resuming workflow for AISOS-XXXX
Re-invoking workflow from review_response_gate
Review response gate: pausing for AISOS-XXXX
Workflow completed for AISOS-XXXX, final node: review_response_gate, paused: True

Root cause

The retry handler at src/forge/orchestrator/worker.py line 1186-1204 clears revision_requested, feedback_comment, and last_error, but does not clear contested_comments. Without that, review_response_gate has no way to know the previous contested state was resolved, so it re-pauses unconditionally.

Suggested fix

Add contested_comments to the fields cleared by the retry handler when at review_response_gate:

updated_state["contested_comments"] = []

Additionally, consider whether the retry at review_response_gate should set current_node to human_review_gate so the workflow returns to accepting PR review events rather than re-entering the same gate.