feat(sync): add GoMag API client with Phase 0 auto-download

- New gomag_client.py service: async httpx client that downloads orders
  from GoMag API with full pagination and 1s rate-limit sleep
- config.py: add GOMAG_API_KEY, GOMAG_API_SHOP, GOMAG_ORDER_DAYS_BACK,
  GOMAG_LIMIT, GOMAG_API_URL settings
- sync_service.py: Phase 0 downloads fresh orders before reading JSONs;
  graceful skip if API keys not configured
- start.sh: auto-detect INSTANTCLIENTPATH from .env, fallback to thin mode
- .env.example: document GoMag API variables

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/app/services/sync_service.py

@@ -4,7 +4,7 @@ import logging
 import uuid
 from datetime import datetime, timedelta
 
-from . import order_reader, validation_service, import_service, sqlite_service, invoice_service
+from . import order_reader, validation_service, import_service, sqlite_service, invoice_service, gomag_client
 from ..config import settings
 from .. import database
 
@@ -122,9 +122,22 @@ async def run_sync(id_pol: int = None, id_sectie: int = None, run_id: str = None
             f"Inceput: {started_dt.strftime('%d.%m.%Y %H:%M:%S')}",
             ""
         ]
-        _log_line(run_id, "Citire fisiere JSON...")
+
+        json_dir = settings.JSON_OUTPUT_DIR
 
         try:
+            # Phase 0: Download orders from GoMag API
+            _update_progress("downloading", "Descărcare comenzi din GoMag API...")
+            _log_line(run_id, "Descărcare comenzi din GoMag API...")
+            dl_result = await gomag_client.download_orders(
+                json_dir, log_fn=lambda msg: _log_line(run_id, msg)
+            )
+            if dl_result["files"]:
+                _log_line(run_id, f"GoMag: {dl_result['total']} comenzi în {dl_result['pages']} pagini → {len(dl_result['files'])} fișiere")
+
+            _update_progress("reading", "Citire fisiere JSON...")
+            _log_line(run_id, "Citire fisiere JSON...")
+
             # Step 1: Read orders and sort chronologically (oldest first - R3)
             orders, json_count = order_reader.read_json_orders()
             orders.sort(key=lambda o: o.date or '')