fix(rdd): surface and advance manual reviewer collection

[llonllon]

Before submitting

• I searched open and closed issues and did not find a report of this problem.
• I reviewed this report and removed credentials, tokens, private paths, hostnames, and other sensitive data.

Problem

A high-risk native review can enter action=collect with replayability=manual_action_required and remain indefinitely idle. The controller returns complete materializable reviewer bindings, but neither launches them nor prominently reports that no background work is running and that the parent orchestrator must submit the whole group. This makes a user reasonably believe review is progressing when it is not.

Steps to reproduce

1. Start an ordinary committed-range review for a high-risk candidate.
2. Call review status after start.
3. Observe action=collect, reason_code=reviewer_results_required, and complete materialize bindings.
4. Do not manually invoke the complete capture group.
5. Observe that the review remains in reviewing with no progress or explicit idle indication.

Expected and actual behavior

Expected:

• The harness either launches the complete provider-issued reviewer group automatically, or prominently reports that collection is idle and requires one group-capture action.
• Status distinguishes waiting for review execution from review execution in progress.

Actual:

• The review remains in reviewing/collect with no background activity.
• Progress resumes only after the parent explicitly invokes the provider-issued complete capture group.

gentle-pi version

3.7.0

Pi version

0.87.1

Operating system

Linux

Relevant logs or error output (optional)

state=reviewing
action=collect
replayability=manual_action_required
reason_code=reviewer_results_required