feat(security): JWT required on every API route, gated dev fallback, role checks

- main.py: global get_current_user dependency on all routers except
  /auth/login and /health; prod fail-fast startup guard rejects wildcard
  CORS, default credentials, DEV_LOGIN_ENABLED
- inventory/pm: X-User-Role header identity fallback now only active when
  PROCUREMENT_DEV_LOGIN_ENABLED=true (was unconditional in production)
- item_decisions writes + attachment deletes: require_role(
  procurement_manager, admin) — require_role was defined but never used
- config.py: ENVIRONMENT flag, comma-separated CORS_ORIGINS, no default
  Casdoor client secret/admin password, DEV_LOGIN_ENABLED=false
- frontend: authenticated file downloads (Bearer + blob) — <a href> links
  cannot send the token; FileList/QuoteDetail/AcceptModal/EditModal/
  PurchaseHistory converted; DEV_LOGIN_ENABLED build arg defaults false
- smoke tests authenticate via POST /auth/login (SMOKE_USER/SMOKE_PASSWORD)
- traefik: security headers, API rate limit, 12MB body cap (prod overlay)
- nginx client_max_body_size aligned to 12MB

backend/app/routers/pm.py

@@ -19,8 +19,9 @@ Rules enforced here:
   the canonical unit for auto-posted purchases.
 - quote.status flips to 'arrived' when ALL chosen items are fully received.
 
-Auth: Casdoor JWT primary; dev fallback headers (X-User-Role: pm|admin +
-X-Project-Id for pm) when no Authorization header — same pattern as the
+Auth: Casdoor JWT (a global dependency in main.py) resolves the caller;
+optional dev-header fallback (X-User-Role: pm|admin + X-Project-Id for pm)
+exists only when PROCUREMENT_DEV_LOGIN_ENABLED=true — same pattern as the
 inventory router.
 """
 import base64
@@ -35,6 +36,7 @@ from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth import UserContext, get_optional_user
+from app.config import settings
 from app.db.engine import get_db
 from app.models.catalog import BrandMaterial, Material, MaterialCategory, Unit
 from app.models.inventory import InventoryItem, InventoryTransaction, Warehouse
@@ -98,9 +100,12 @@ async def arrivals_scope(
             if ctx.role in ("admin", "procurement_manager"):
                 return ArrivalScope(role="admin", user_id=ctx.user.id, project_id=project_id, display_name=ctx.display_name)
             raise ForbiddenError("این بخش فقط برای مدیر پروژه یا مدیر تدارکات است")
-    # Dev fallback: X-User-Role: pm | admin (procurement_manager maps to admin)
-    if not request.headers.get("x-user-role"):
-        raise UnauthorizedError("احراز هویت لازم است — توکن Casdoor یا حالت توسعه را ارسال کنید")
+    # Dev fallback: X-User-Role: pm | admin (procurement_manager maps to
+    # admin) — ONLY when DEV_LOGIN_ENABLED (local testing without Casdoor).
+    # Disabled by default: an ungated header identity in production would
+    # let anyone confirm receipts as PM.
+    if not settings.DEV_LOGIN_ENABLED or not request.headers.get("x-user-role"):
+        raise UnauthorizedError("احراز هویت لازم است — توکن Casdoor ارسال کنید")
     role = (request.headers.get("x-user-role") or "").strip().lower()
     if role == "procurement_manager":
         role = "admin"