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/brands.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
 from app.schemas.catalog import BrandCreate, BrandUpdate
@@ -12,7 +11,6 @@ from app.utils.pagination import paginate, sort_query
 from app.utils.serialization import to_iso
 
 router = APIRouter(prefix="/brands", tags=["brands"])
-_procurement_writer = require_role("admin", "procurement_manager")
 
 
 def brand_to_dict(brand: Brand) -> dict:
@@ -44,11 +42,7 @@ async def list_brands(
 
 
 @router.post("", status_code=201)
-async def create_brand(
-    payload: BrandCreate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def create_brand(payload: BrandCreate, db: AsyncSession = Depends(get_db)):
     rows = (await db.execute(select(Brand).where(Brand.name == payload.name))).scalars().all()
     if any(b.country == payload.country for b in rows):
         raise ConflictError("برندی با این نام و کشور قبلاً ثبت شده است")
@@ -67,12 +61,7 @@ async def get_brand(brand_id, db: AsyncSession = Depends(get_db)):
 
 
 @router.patch("/{brand_id}")
-async def update_brand(
-    brand_id,
-    payload: BrandUpdate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def update_brand(brand_id, payload: BrandUpdate, db: AsyncSession = Depends(get_db)):
     brand = await db.get(Brand, brand_id)
     if brand is None:
         raise NotFoundError("برند یافت نشد")
@@ -90,11 +79,7 @@ async def update_brand(
 
 
 @router.delete("/{brand_id}")
-async def delete_brand(
-    brand_id,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def delete_brand(brand_id, db: AsyncSession = Depends(get_db)):
     brand = await db.get(Brand, brand_id)
     if brand is None:
         raise NotFoundError("برند یافت نشد")