Add required human review gate to the Agent pipeline.

Agent web jobs now stop after Brain consolidation and enter needs_review
with a persisted review queue (blocking: high-severity, low-confidence,
sensitive-category findings; audit sample of clean clusters). Humans
decide confirm/reject/unsure/needs_clarification via new review API and
frontend queue; a finalizer applies decisions (rejections suppressed with
reason codes), performs bounded targeted reruns for clarifications,
drafts RFIs only for kept issues, and only then marks the job done and
sends the final email. Two-phase email (review-required, then final
report), per-decision feedback labels with redacted aggregate metrics,
restart recovery from job artifacts, and CLI --no-review bypass.
Classic pipeline unchanged. 65 non-LLM tests.

backend/.env.example

@@ -27,6 +27,13 @@ AGENT_CONFLICT_CONCURRENCY=4
 AGENT_SPECIALIST_CONCURRENCY=4
 AGENT_RFI_CONCURRENCY=4
 
+# Agent-mode human-review gate (pipeline stops after Brain until a human reviews)
+AGENT_REQUIRE_REVIEW=true
+# Max clean clusters added to the review queue as non-blocking spot-checks
+AGENT_REVIEW_AUDIT_SAMPLE=5
+# Allow future cross-job review-feedback aggregation to include source_text/images/comments
+REVIEW_AGGREGATE_INCLUDE_TEXT=false
+
 # Pipeline tuning
 PDF_DPI=100
 MAX_PAGES=60