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/static/js/shared.js

@@ -865,9 +865,13 @@ async function renderOrderDetailModal(orderNumber, opts) {
         // Render compact header info (partner + addresses)
         _renderHeaderInfo(order);
 
-        if (order.error_message) {
-            document.getElementById('detailError').textContent = order.error_message;
-            document.getElementById('detailError').style.display = '';
+        const detailErrEl = document.getElementById('detailError');
+        if (order.oracle_available === false) {
+            detailErrEl.textContent = '⚠ Oracle indisponibil — CODMAT-urile nu pot fi incarcate momentan. Reincearca dupa restabilirea conexiunii.';
+            detailErrEl.style.display = '';
+        } else if (order.error_message) {
+            detailErrEl.textContent = order.error_message;
+            detailErrEl.style.display = '';
         }
 
         // Configure footer action buttons BEFORE any early-return on items —