Revert 253c922: restore the PM/RBAC work to the integration

Reverting the production revert so the pm branch can merge cleanly on
top of the restored RBAC base. Conflicts against newer integration work
resolved by combining:
- App.tsx: v7's bot-draft wizard bypass + login returnUrl kept alongside
  the supervisor gating (no-project block screen, panel scoping)
- LoginPage: returnUrl navigation kept, supervisor routing added
- migration.sql: bot_drafts table kept, unified-projects ALTERs restored

backend/app/routers/supplier_materials.py

@@ -8,6 +8,7 @@ from fastapi import APIRouter, Depends, Query
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from app.auth import require_role
 from app.db.engine import get_db
 from app.models.catalog import Material, MaterialCategory
 from app.models.procurement import Supplier, SupplierMaterial
@@ -18,6 +19,7 @@ from app.utils.pagination import paginate
 from app.utils.serialization import to_iso
 
 router = APIRouter(tags=["supplier-materials"])
+_procurement_writer = require_role("admin", "procurement_manager")
 
 
 def link_to_dict(link: SupplierMaterial, material: Material | None = None,
@@ -63,7 +65,10 @@ async def list_supplier_materials(
 
 @router.post("/suppliers/{supplier_id}/materials", status_code=201)
 async def create_supplier_material(
-    supplier_id, payload: SupplierMaterialCreate, db: AsyncSession = Depends(get_db)
+    supplier_id,
+    payload: SupplierMaterialCreate,
+    db: AsyncSession = Depends(get_db),
+    _auth=Depends(_procurement_writer),
 ):
     async with db.begin():
         link = await link_supplier_material(db, supplier_id, payload.material_id)
@@ -72,7 +77,12 @@ async def create_supplier_material(
 
 
 @router.delete("/suppliers/{supplier_id}/materials/{material_id}")
-async def delete_supplier_material(supplier_id, material_id, db: AsyncSession = Depends(get_db)):
+async def delete_supplier_material(
+    supplier_id,
+    material_id,
+    db: AsyncSession = Depends(get_db),
+    _auth=Depends(_procurement_writer),
+):
     async with db.begin():
         await unlink_supplier_material(db, supplier_id, material_id)
     return {"data": {"supplier_id": str(supplier_id), "material_id": str(material_id), "deleted": True}}