feat(oracle): auto-recover Oracle pool + surface status, stop silent import failures

After a power loss the app started before Oracle was ready; init_oracle() failed
once, the pool stayed None forever (no retry), and every sync silently failed
("Oracle pool not initialized") while still hammering the GoMag API each minute,
and order-detail 500'd.

- database.ensure_oracle_pool(force): thread-safe (re)create of the pool, called
  at the start of every sync cycle → self-heals within one cycle once Oracle is
  back (incl. after an Oracle service restart). init_oracle_client made idempotent
  so re-init can't fall back to thin mode.
- database.oracle_status() exposed; main.py startup is non-fatal via ensure pool.
- run_sync ensures the pool before the GoMag download; on failure it records a
  clear run status instead of crashing and skips the wasted API calls.
- /api/sync/health reports oracle_ready/last_error; dashboard health pill shows
  "Oracle indisponibil" (top priority). Recovery via the existing Start Sync button.
- order_detail degrades gracefully (200 without CODMAT + notice) instead of 500.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

api/app/services/sync_service.py

@@ -338,6 +338,26 @@ async def run_sync(id_pol: int = None, id_sectie: int = None, run_id: str = None
             return {"run_id": run_id, "status": "halted_escalation", "error": halt_msg}
 
         try:
+            # Phase -1: Ensure Oracle pool (auto-recovery after a DB restart).
+            # Done before the GoMag download so we don't waste API calls every
+            # cycle while Oracle is down, and so users get a clear status.
+            if not await asyncio.to_thread(database.ensure_oracle_pool):
+                last_err = database.oracle_status().get("last_error") or "fara detalii"
+                msg = ("Oracle indisponibil — pool neinitializat. Import oprit; "
+                       "se reincearca automat la urmatorul ciclu de sync. "
+                       f"Detalii: {last_err}")
+                _log_line(run_id, f"EROARE: {msg}")
+                await sqlite_service.create_sync_run(run_id, 0)
+                await sqlite_service.update_sync_run(
+                    run_id, "failed", 0, 0, 0, 0, error_message=msg
+                )
+                if _current_sync:
+                    _current_sync["status"] = "failed"
+                    _current_sync["finished_at"] = _now().isoformat()
+                    _current_sync["error"] = msg
+                _update_progress("failed", "Oracle indisponibil — import oprit")
+                return {"run_id": run_id, "status": "failed", "error": msg}
+
             # Phase 0: Download orders from GoMag API
             _update_progress("downloading", "Descărcare comenzi din GoMag API...")
             _log_line(run_id, "Descărcare comenzi din GoMag API...")