Add API Q1 CAPA: root cause, corrective action gate, effectiveness verification

Implements tester feedback against API Q1 §5.9.1.2 / §6.4.2:

- Root Cause field + 6M Root Cause Category lookup (Man/Machine/Method/
  Material/Measurement/Environment), separate from Deviation Detail/Category
- "Corrective Action Required?" Yes/No gate on every NCR with a required
  justification
- Corrective action plan with owner + due date; owner is notified by email
- Effectiveness verification (result, notes, server-stamped verifier/date)
  required before an NCR can close when corrective action is required —
  costing returns 409 listing the missing pieces
- Recurring-issue flag with bidirectional NCR-to-NCR links; prior NCRs show
  a warning when later NCRs reference them
- Dashboard metrics: % root cause completed, % CAPA verified effective,
  avg CAPA close time, overdue CAPA count, NCRs by root cause category
- CAPA section in the NCR detail UI, printable PDF, CSV export, and the
  vw_ncr_full Power BI view; admin list manager for root cause categories
- Migrations 0003 (schema + seeded 6M lookup) and 0004 (view refresh);
  demo seed data exercises every metric

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/app/routers/lookups.py

@@ -4,41 +4,34 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth.deps import CurrentUser, get_current_user
 from app.database import get_db
-from app.models import Department, DeviationCategory
+from app.models import Department, DeviationCategory, RootCauseCategory
 from app.schemas.lookup import LookupsOut, NamedLookupOut
 
 router = APIRouter(tags=["lookups"])
 
 
+async def _active(db: AsyncSession, model) -> list[NamedLookupOut]:
+    rows = (
+        (
+            await db.execute(
+                select(model).where(model.is_active.is_(True)).order_by(model.name)
+            )
+        )
+        .scalars()
+        .all()
+    )
+    return [NamedLookupOut.model_validate(r) for r in rows]
+
+
 @router.get("/lookups", response_model=LookupsOut)
 async def get_lookups(
     _: CurrentUser = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ) -> LookupsOut:
-    """Active departments and deviation categories for form dropdowns."""
-    departments = (
-        (
-            await db.execute(
-                select(Department)
-                .where(Department.is_active.is_(True))
-                .order_by(Department.name)
-            )
-        )
-        .scalars()
-        .all()
-    )
-    categories = (
-        (
-            await db.execute(
-                select(DeviationCategory)
-                .where(DeviationCategory.is_active.is_(True))
-                .order_by(DeviationCategory.name)
-            )
-        )
-        .scalars()
-        .all()
-    )
+    """Active departments, deviation categories, and root cause categories
+    for form dropdowns."""
     return LookupsOut(
-        departments=[NamedLookupOut.model_validate(d) for d in departments],
-        deviation_categories=[NamedLookupOut.model_validate(c) for c in categories],
+        departments=await _active(db, Department),
+        deviation_categories=await _active(db, DeviationCategory),
+        root_cause_categories=await _active(db, RootCauseCategory),
     )