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/line_item_specs.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.catalog import AttributeDefinition, Unit
 from app.models.procurement import LineItem, LineItemSpec, Quote
@@ -13,7 +12,6 @@ from app.services.eav_service import flatten_eav_values
 from app.utils.errors import ConflictError, NotFoundError
 
 router = APIRouter(prefix="/quotes/{quote_id}/line-items/{line_item_id}/specs", tags=["line-item-specs"])
-_procurement_writer = require_role("admin", "procurement_manager")
 
 
 async def _line_item_or_404(db: AsyncSession, quote_id, line_item_id) -> LineItem:
@@ -55,13 +53,7 @@ async def get_line_item_specs(quote_id, line_item_id, db: AsyncSession = Depends
 
 
 @router.put("")
-async def put_line_item_specs(
-    quote_id,
-    line_item_id,
-    payload: SpecsPutIn,
-    db: AsyncSession = Depends(get_db),
-    _auth=Depends(_procurement_writer),
-):
+async def put_line_item_specs(quote_id, line_item_id, payload: SpecsPutIn, db: AsyncSession = Depends(get_db)):
     """FULL replacement — specs not in the payload are DELETED (P1-19)."""
     async with db.begin():
         li = await _line_item_or_404(db, quote_id, line_item_id)