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/templates/base.html

@@ -169,7 +169,7 @@
 
     <script>window.ROOT_PATH = "{{ rp }}";</script>
     <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js"></script>
-    <script src="{{ rp }}/static/js/shared.js?v=50"></script>
+    <script src="{{ rp }}/static/js/shared.js?v=51"></script>
     <script>
     // Dark mode toggle
     function toggleDarkMode() {