feat: refocus on drawings — code/ADA gated off, drawing-integrity wave, Brain-directed clarification

- ENABLE_CODE_REVIEW flag (default off): skips code/ADA/jurisdiction review
  path in both pipelines; nothing deleted, one env flag to restore.
- Per-sheet Drawing Integrity QA wave (agent + classic, default on):
  dangling refs, on-sheet contradictions, dimension sanity, missing sheet
  essentials, tag hygiene. New DrawingIntegrityAgent + classic stage.
- Broadened conflict critic: intra-sheet + same-discipline contradictions,
  not just cross-discipline.
- Wave 6.5 Brain-directed clarification (bounded hub-and-spoke): Brain names
  uncertain findings, verify_evidence requests route through the wave-5b
  verifier; refuted findings suppressed. One planning call + capped verifies,
  single iteration. Shared _build_verify_scopes across 5b and 6.5.
- Config knobs, .env.example, frontend copy, tests (182 passing).

tests/agents/test_review_focus_gating.py

@@ -0,0 +1,102 @@
+"""Flag-gating tests: ENABLE_CODE_REVIEW off skips code, drawing_integrity runs.
+
+Runner-level smoke tests using stubbed agents (same pattern as
+test_wave5b_suppression). Verifies the code/ADA wave is skipped when
+ENABLE_CODE_REVIEW is false and the Drawing Integrity wave feeds findings
+into the report by_stage counters.
+"""
+
+import backend.agents.runner as runner_mod
+from backend import config
+from backend.agents.base import AgentResult
+from backend.agents.runner import run_agent_pipeline
+
+
+def _stub_agent(artifacts):
+    return lambda usage: type("S", (), {
+        "name": "stub",
+        "run": lambda self, scope: AgentResult(
+            scope_id=scope.scope_id, artifacts=list(artifacts)),
+    })()
+
+
+def _integrity_finding():
+    return {
+        "issue_id": "DI-1", "severity": "high", "confidence": "high",
+        "source_stage": "drawing_integrity", "sheets": ["A101"],
+        "category": "dangling_reference",
+        "description": "Detail callout 5/A101 has no detail 5 on this sheet",
+        "evidence": [{"sheet": "A101", "source_text": "5/A101"}],
+    }
+
+
+def _patch(monkeypatch, code_should_raise):
+    monkeypatch.setattr(
+        runner_mod, "convert_pdf_to_images",
+        lambda path: [{"page_number": 1, "base64": "QUJD"}])
+    # Sheet has 3+ assertions so the integrity wave does NOT skip it.
+    monkeypatch.setattr(runner_mod, "SheetExtractorAgent", _stub_agent([
+        {"sheet_number": "A101", "page_number": 1, "level": "1",
+         "discipline": "A", "assertions": [
+             {"text": "5/A101", "object_type": "detail_marker"},
+             {"text": "ROOM 101", "object_type": "room"},
+             {"text": "DOOR 101A", "object_type": "door"},
+         ]},
+    ]))
+    monkeypatch.setattr(runner_mod, "SheetIndexAgent", _stub_agent([{}]))
+    monkeypatch.setattr(runner_mod, "JurisdictionAgent", _stub_agent([{}]))
+    monkeypatch.setattr(runner_mod, "LinkerAgent", _stub_agent([]))
+    monkeypatch.setattr(runner_mod, "ConflictCriticAgent", _stub_agent([]))
+
+    def code_boom(usage):
+        if code_should_raise:
+            raise AssertionError("CodeAgent must not run when gated off")
+        return _stub_agent([])(usage)
+    monkeypatch.setattr(runner_mod, "CodeAgent", code_boom)
+
+    monkeypatch.setattr(runner_mod, "DrawingIntegrityAgent",
+                        _stub_agent([_integrity_finding()]))
+    monkeypatch.setattr(runner_mod, "ConstructabilityAgent", _stub_agent([]))
+    monkeypatch.setattr(runner_mod, "CompletenessAgent", _stub_agent([]))
+    monkeypatch.setattr(
+        runner_mod, "BrainAgent",
+        lambda usage: type("B", (), {
+            "run": lambda self, findings, si, ju: (list(findings), []),
+            "plan_clarifications": lambda self, prioritized: []})())
+    # Stub the wave-5b verifier so the high-severity integrity finding is
+    # confirmed (never a live network call).
+    monkeypatch.setattr(
+        "backend.agents.verifier.call_json",
+        lambda **kwargs: {"verdicts": [
+            {"sheet": "A101", "source_text": "5/A101",
+             "verdict": "confirmed", "actual_text": None, "notes": None},
+        ]})
+
+
+def test_code_gated_off_integrity_on(monkeypatch, tmp_path):
+    monkeypatch.setattr(config, "ENABLE_CODE_REVIEW", False)
+    monkeypatch.setattr(config, "ENABLE_DRAWING_INTEGRITY", True)
+    _patch(monkeypatch, code_should_raise=True)
+    pdf = tmp_path / "d.pdf"
+    pdf.write_bytes(b"%PDF-1.4\n")
+    report = run_agent_pipeline(str(pdf), out_dir=str(tmp_path),
+                                require_review=False)
+    by_stage = report["summary"]["by_stage"]
+    assert by_stage["code"] == 0
+    assert by_stage["drawing_integrity"] == 1
+    # The integrity finding survived into the validated set.
+    assert any(f.get("issue_id") == "DI-1"
+               for f in report.get("validated_issues") or [])
+
+
+def test_code_enabled_runs(monkeypatch, tmp_path):
+    monkeypatch.setattr(config, "ENABLE_CODE_REVIEW", True)
+    monkeypatch.setattr(config, "ENABLE_DRAWING_INTEGRITY", True)
+    _patch(monkeypatch, code_should_raise=False)
+    # build_code_scopes runs on the real sheet; CodeAgent is stubbed to []
+    pdf = tmp_path / "d.pdf"
+    pdf.write_bytes(b"%PDF-1.4\n")
+    report = run_agent_pipeline(str(pdf), out_dir=str(tmp_path),
+                                require_review=False)
+    # No crash; integrity still reported.
+    assert report["summary"]["by_stage"]["drawing_integrity"] == 1