revert: restore production to the state before 730d0bd (PM/RBAC work moved to 'pm')

Their three commits (730d0bd, 5a9b543, 387edfb) reached production by push and
auto-deployed. 387edfb expects a users.username column that the live database does
not have, so POST /api/v1/auth/login was returning HTTP 500. Their schema changes
never applied either (projects still has only id, name, description, start_date,
pm_user_id, created_at), so nothing depends on the reverted code.

This commit sets the tree back to exactly a02b3ea — verified with git diff against
it — while keeping history linear: the work itself is preserved on 'pm' at 387edfb.

backend/app/routers/brand_materials.py

@@ -3,7 +3,6 @@ from fastapi import APIRouter, Depends, Query
 from sqlalchemy import func, 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 Brand, BrandMaterial, Material
 from app.models.procurement import LineItem
@@ -13,7 +12,6 @@ from app.utils.pagination import paginate, sort_query
 from app.utils.serialization import to_iso
 
 router = APIRouter(prefix="/brand-materials", tags=["brand-materials"])
-_procurement_writer = require_role("admin", "procurement_manager")
 
 
 def bm_to_dict(bm: BrandMaterial, expand: set[str] = frozenset()) -> dict:
@@ -72,11 +70,7 @@ async def list_brand_materials(
 
 
 @router.post("", status_code=201)
-async def create_brand_material(
-    payload: BrandMaterialCreate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def create_brand_material(payload: BrandMaterialCreate, db: AsyncSession = Depends(get_db)):
     if await db.get(Brand, payload.brand_id) is None:
         raise NotFoundError("برند یافت نشد", field="brand_id")
     if await db.get(Material, payload.material_id) is None:
@@ -113,12 +107,7 @@ async def get_brand_material(bm_id, expand: str | None = None, db: AsyncSession
 
 
 @router.patch("/{bm_id}")
-async def update_brand_material(
-    bm_id,
-    payload: BrandMaterialUpdate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def update_brand_material(bm_id, payload: BrandMaterialUpdate, db: AsyncSession = Depends(get_db)):
     bm = await db.get(BrandMaterial, bm_id)
     if bm is None:
         raise NotFoundError("ارتباط برند-متریال یافت نشد")
@@ -131,11 +120,7 @@ async def update_brand_material(
 
 
 @router.delete("/{bm_id}")
-async def delete_brand_material(
-    bm_id,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def delete_brand_material(bm_id, db: AsyncSession = Depends(get_db)):
     bm = await db.get(BrandMaterial, bm_id)
     if bm is None:
         raise NotFoundError("ارتباط برند-متریال یافت نشد")