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/gomag_client.py

@@ -0,0 +1,88 @@
+"""GoMag API client - downloads orders and saves them as JSON files."""
+import asyncio
+import json
+import logging
+from datetime import datetime, timedelta
+from pathlib import Path
+from typing import Callable
+
+import httpx
+
+from ..config import settings
+
+logger = logging.getLogger(__name__)
+
+
+async def download_orders(
+    json_dir: str,
+    days_back: int = None,
+    log_fn: Callable[[str], None] = None,
+) -> dict:
+    """Download orders from GoMag API and save as JSON files.
+
+    Returns dict with keys: pages, total, files (list of saved file paths).
+    If API keys are not configured, returns immediately with empty result.
+    """
+    def _log(msg: str):
+        logger.info(msg)
+        if log_fn:
+            log_fn(msg)
+
+    if not settings.GOMAG_API_KEY or not settings.GOMAG_API_SHOP:
+        _log("GoMag API keys neconfigurați, skip download")
+        return {"pages": 0, "total": 0, "files": []}
+
+    if days_back is None:
+        days_back = settings.GOMAG_ORDER_DAYS_BACK
+
+    start_date = (datetime.now() - timedelta(days=days_back)).strftime("%Y-%m-%d")
+    out_dir = Path(json_dir)
+    out_dir.mkdir(parents=True, exist_ok=True)
+
+    headers = {
+        "Apikey": settings.GOMAG_API_KEY,
+        "ApiShop": settings.GOMAG_API_SHOP,
+        "User-Agent": "Mozilla/5.0",
+        "Content-Type": "application/json",
+    }
+
+    saved_files = []
+    total_orders = 0
+    total_pages = 1
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+
+    async with httpx.AsyncClient(timeout=30) as client:
+        page = 1
+        while page <= total_pages:
+            params = {
+                "startDate": start_date,
+                "page": page,
+                "limit": settings.GOMAG_LIMIT,
+            }
+            try:
+                response = await client.get(settings.GOMAG_API_URL, headers=headers, params=params)
+                response.raise_for_status()
+                data = response.json()
+            except httpx.HTTPError as e:
+                _log(f"GoMag API eroare pagina {page}: {e}")
+                break
+            except Exception as e:
+                _log(f"GoMag eroare neașteptată pagina {page}: {e}")
+                break
+
+            # Update totals from first page response
+            if page == 1:
+                total_orders = int(data.get("total", 0))
+                total_pages = int(data.get("pages", 1))
+                _log(f"GoMag: {total_orders} comenzi în {total_pages} pagini (startDate={start_date})")
+
+            filename = out_dir / f"gomag_orders_page{page}_{timestamp}.json"
+            filename.write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")
+            saved_files.append(str(filename))
+            _log(f"GoMag: pagina {page}/{total_pages} salvată → {filename.name}")
+
+            page += 1
+            if page <= total_pages:
+                await asyncio.sleep(1)
+
+    return {"pages": total_pages, "total": total_orders, "files": saved_files}