refactor(status): introduce OrderStatus enum, replace string literals

Centralized order status values in api/app/constants.py via a
str-valued Enum so comparisons keep working. Replaced literals in:
- services: sync_service, sqlite_service, retry_service
- routers: sync, dashboard
- templates: dashboard.html, logs.html
- static JS: shared (ORDER_STATUS mirror), dashboard, logs
- tests: requirements, order_items_overwrite, business_rules

MALFORMED intentionally NOT added — introduced in follow-up PR2
(per-order failure isolation).

Full test suite: 231 unit + 33 e2e pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/app/services/retry_service.py

@@ -4,6 +4,8 @@ import logging
 import tempfile
 from datetime import datetime, timedelta
 
+from ..constants import OrderStatus
+
 logger = logging.getLogger(__name__)
 
 
@@ -70,7 +72,7 @@ async def _download_and_reimport(order_number: str, order_date_str: str, custome
             order_number=order_number,
             order_date=order_date_str,
             customer_name=customer_name,
-            status="ERROR",
+            status=OrderStatus.ERROR.value,
             error_message=f"Retry failed: {e}",
         )
         return {"success": False, "message": f"Eroare import: {e}"}
@@ -103,7 +105,7 @@ async def _download_and_reimport(order_number: str, order_date_str: str, custome
             order_number=order_number,
             order_date=order_date_str,
             customer_name=customer_name,
-            status="IMPORTED",
+            status=OrderStatus.IMPORTED.value,
             id_comanda=result.get("id_comanda"),
             id_partener=result.get("id_partener"),
             error_message=None,
@@ -116,7 +118,7 @@ async def _download_and_reimport(order_number: str, order_date_str: str, custome
             )
         await sqlite_service.add_order_items(order_number, order_items_data)
         logger.info(f"Retry successful for order {order_number} → IMPORTED ({len(order_items_data)} items)")
-        return {"success": True, "message": "Comanda reimportata cu succes", "status": "IMPORTED"}
+        return {"success": True, "message": "Comanda reimportata cu succes", "status": OrderStatus.IMPORTED.value}
     else:
         error = result.get("error", "Unknown error")
         await sqlite_service.upsert_order(
@@ -124,11 +126,11 @@ async def _download_and_reimport(order_number: str, order_date_str: str, custome
             order_number=order_number,
             order_date=order_date_str,
             customer_name=customer_name,
-            status="ERROR",
+            status=OrderStatus.ERROR.value,
             error_message=f"Retry: {error}",
         )
         await sqlite_service.add_order_items(order_number, order_items_data)
-        return {"success": False, "message": f"Import esuat: {error}", "status": "ERROR"}
+        return {"success": False, "message": f"Import esuat: {error}", "status": OrderStatus.ERROR.value}
 
 
 async def retry_single_order(order_number: str, app_settings: dict) -> dict:
@@ -157,7 +159,7 @@ async def retry_single_order(order_number: str, app_settings: dict) -> dict:
 
     order_data = detail["order"]
     status = order_data.get("status", "")
-    if status not in ("ERROR", "SKIPPED", "DELETED_IN_ROA"):
+    if status not in (OrderStatus.ERROR.value, OrderStatus.SKIPPED.value, OrderStatus.DELETED_IN_ROA.value):
         return {"success": False, "message": f"Retry permis doar pentru ERROR/SKIPPED/DELETED_IN_ROA (status actual: {status})"}
 
     order_date_str = order_data.get("order_date", "")
@@ -196,7 +198,7 @@ async def resync_single_order(order_number: str, app_settings: dict) -> dict:
     status = order_data.get("status", "")
     id_comanda = order_data.get("id_comanda")
 
-    if status not in ("IMPORTED", "ALREADY_IMPORTED") or not id_comanda:
+    if status not in (OrderStatus.IMPORTED.value, OrderStatus.ALREADY_IMPORTED.value) or not id_comanda:
         return {"success": False, "message": f"Resync permis doar pentru IMPORTED/ALREADY_IMPORTED cu id_comanda (status actual: {status})"}
 
     # Invoice safety gate
@@ -269,7 +271,7 @@ async def delete_single_order(order_number: str) -> dict:
     status = order_data.get("status", "")
     id_comanda = order_data.get("id_comanda")
 
-    if status not in ("IMPORTED", "ALREADY_IMPORTED") or not id_comanda:
+    if status not in (OrderStatus.IMPORTED.value, OrderStatus.ALREADY_IMPORTED.value) or not id_comanda:
         return {"success": False, "message": f"Stergere permisa doar pentru IMPORTED/ALREADY_IMPORTED cu id_comanda (status actual: {status})"}
 
     # Invoice safety gate