Frontend: Reviewer queue, review packet, decision, and findings UI

[Abiorh001]

Parent: #29
Depends on: #50, #34, #35, #37

Why

Week 3 explicitly calls for reviewer queue, review page, checker result panel, task guide panel, submission evidence panel, and review decision form. This is not covered by backend issues alone.

Roadmap Source

• docs/roadmap_day_by_day_execution_plan.md Days 11-15
• docs/operations_reviewer_workflow.md
• docs/product_first_user_flows.md Flow 5

Scope

• Reviewer queue view.
• Review packet view with guide, task, submission, evidence, checker results, prior findings, and revision replay.
• Structured findings form.
• Decision form for accept, needs_revision, reject.
• Reviewer quality/second-review indicators where backend data exists.

Acceptance Criteria

• Reviewer can make a valid decision only when backend requirements are satisfied.
• needs_revision and reject forms require findings.
• accept requires evidence references/checklist confirmation.
• UI clearly distinguishes checker-caused revision from human review revision.
• Tests/demo evidence cover accept, needs_revision, and reject paths.

Contributor Fit

Core frontend issue for a contributor after review backend contracts land.