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/standard_conversions.py

@@ -3,7 +3,6 @@ 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 StandardConversion
 from app.schemas.catalog import StandardConversionCreate, StandardConversionUpdate
@@ -12,7 +11,6 @@ from app.utils.pagination import paginate
 from app.utils.serialization import to_iso
 
 router = APIRouter(prefix="/standard-conversions", tags=["standard-conversions"])
-_procurement_writer = require_role("admin", "procurement_manager")
 
 
 def sc_to_dict(sc: StandardConversion) -> dict:
@@ -43,11 +41,7 @@ async def list_standard_conversions(
 
 
 @router.post("", status_code=201)
-async def create_standard_conversion(
-    payload: StandardConversionCreate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def create_standard_conversion(payload: StandardConversionCreate, db: AsyncSession = Depends(get_db)):
     duplicate = await db.scalar(
         select(StandardConversion.id).where(
             StandardConversion.from_unit == payload.from_unit,
@@ -73,12 +67,7 @@ async def get_standard_conversion(sc_id, db: AsyncSession = Depends(get_db)):
 
 
 @router.patch("/{sc_id}")
-async def update_standard_conversion(
-    sc_id,
-    payload: StandardConversionUpdate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def update_standard_conversion(sc_id, payload: StandardConversionUpdate, db: AsyncSession = Depends(get_db)):
     sc = await db.get(StandardConversion, sc_id)
     if sc is None:
         raise NotFoundError("تبدیل استاندارد یافت نشد")
@@ -105,11 +94,7 @@ async def update_standard_conversion(
 
 
 @router.delete("/{sc_id}")
-async def delete_standard_conversion(
-    sc_id,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def delete_standard_conversion(sc_id, db: AsyncSession = Depends(get_db)):
     sc = await db.get(StandardConversion, sc_id)
     if sc is None:
         raise NotFoundError("تبدیل استاندارد یافت نشد")