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).

backend/agents/brain.py

@@ -6,7 +6,12 @@ from typing import Dict, List, Tuple
 
 from backend import config
 from backend.agents.base import AgentUsage
-from backend.agents.prompts import BRAIN_SYSTEM_PROMPT, BRAIN_USER_PROMPT
+from backend.agents.prompts import (
+    BRAIN_CLARIFY_SYSTEM_PROMPT,
+    BRAIN_CLARIFY_USER_PROMPT,
+    BRAIN_SYSTEM_PROMPT,
+    BRAIN_USER_PROMPT,
+)
 from backend.llm import call_json
 from backend.pipeline._stage import collect_list, validate_issue
 
@@ -127,3 +132,69 @@ class BrainAgent:
         issues.sort(key=lambda item: -int(item.get("risk_score") or 0))
         decisions = parsed.get("decisions") or []
         return issues, [item for item in decisions if isinstance(item, dict)]
+
+    def plan_clarifications(self, prioritized: List[Dict]) -> List[Dict]:
+        """Wave 6.5 planning call: name kept findings the Brain wants to
+        double-check before publishing, as typed clarification requests.
+
+        Returns a capped list of {issue_id, request_type, reason}. Only
+        findings that carry an issue_id and do NOT already have a verification
+        result are offered to the model; anything the model names outside that
+        set, or with an unknown request_type, is dropped by the caller/router.
+        Never raises — a failed/empty plan just yields no requests.
+        """
+        max_requests = config.BRAIN_CLARIFY_MAX_REQUESTS
+        if not prioritized or max_requests <= 0:
+            return []
+        candidates = [
+            {
+                "issue_id": f.get("issue_id"),
+                "severity": f.get("severity"),
+                "confidence": f.get("confidence"),
+                "source_stage": f.get("source_stage"),
+                "description": (f.get("description") or "")[:400],
+                "evidence": f.get("evidence") or [],
+                "already_verified": bool(f.get("verification")),
+            }
+            for f in prioritized
+            if f.get("issue_id") and not f.get("verification")
+        ]
+        if not candidates:
+            return []
+        instruction = (
+            BRAIN_CLARIFY_USER_PROMPT
+            .replace("{max_requests}", str(max_requests))
+            .replace("{findings}", json.dumps(candidates, ensure_ascii=True))
+        )
+        try:
+            parsed = call_json(
+                system_prompt=BRAIN_CLARIFY_SYSTEM_PROMPT,
+                user_text=instruction,
+                max_tokens=config.BRAIN_CLARIFY_MAX_TOKENS,
+                model=config.AGENT_BRAIN_MODEL,
+                usage_tracker=self.usage,
+                usage_stage="agent.brain_clarify",
+            )
+        except Exception:
+            return []
+        raw = parsed.get("requests") if isinstance(parsed, dict) else parsed
+        if not isinstance(raw, list):
+            return []
+        valid_ids = {c["issue_id"] for c in candidates}
+        requests: List[Dict] = []
+        seen: set = set()
+        for item in raw:
+            if not isinstance(item, dict):
+                continue
+            issue_id = item.get("issue_id")
+            if issue_id not in valid_ids or issue_id in seen:
+                continue
+            requests.append({
+                "issue_id": issue_id,
+                "request_type": (item.get("request_type") or "verify_evidence").strip(),
+                "reason": (item.get("reason") or "").strip(),
+            })
+            seen.add(issue_id)
+            if len(requests) >= max_requests:
+                break
+        return requests