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/item_receipts.py

@@ -3,7 +3,6 @@ from fastapi import APIRouter, Depends
 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.procurement import ItemDecision, ItemReceipt, LineItem
 from app.schemas.procurement import ReceiptCreate, ReceiptUpdate
@@ -15,7 +14,6 @@ router = APIRouter(
     prefix="/quotes/{quote_id}/line-items/{line_item_id}/receipt",
     tags=["item-receipts"],
 )
-_procurement_writer = require_role("admin", "procurement_manager")
 
 
 async def _line_item_or_404(db: AsyncSession, quote_id, line_item_id) -> LineItem:
@@ -47,13 +45,7 @@ async def get_receipt(quote_id, line_item_id, db: AsyncSession = Depends(get_db)
 
 
 @router.post("", status_code=201)
-async def create_receipt(
-    quote_id,
-    line_item_id,
-    payload: ReceiptCreate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def create_receipt(quote_id, line_item_id, payload: ReceiptCreate, db: AsyncSession = Depends(get_db)):
     await _line_item_or_404(db, quote_id, line_item_id)
     decision = await _decision_or_404(db, line_item_id)
     existing = await db.scalar(select(ItemReceipt).where(ItemReceipt.item_decision_id == decision.id))
@@ -73,13 +65,7 @@ async def create_receipt(
 
 
 @router.patch("")
-async def update_receipt(
-    quote_id,
-    line_item_id,
-    payload: ReceiptUpdate,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def update_receipt(quote_id, line_item_id, payload: ReceiptUpdate, db: AsyncSession = Depends(get_db)):
     await _line_item_or_404(db, quote_id, line_item_id)
     decision = await db.scalar(select(ItemDecision).where(ItemDecision.line_item_id == line_item_id))
     if decision is None: