feat(sync): add SSE live feed, unified logs page, fix Oracle connection

- Add SSE event bus in sync_service (subscribe/unsubscribe/_emit)
- Add GET /api/sync/stream SSE endpoint for real-time sync progress
- Rewrite logs.html: unified runs table + live feed + summary + filters
- Rewrite logs.js: SSE EventSource client, run selection, pagination
- Dashboard: clickable runs navigate to /logs?run=, sync started banner
- Remove "Import Comenzi" nav item, delete sync_detail.html
- Add error_message column to sync_runs table with migration
- Fix: export TNS_ADMIN as OS env var so oracledb finds tnsnames.ora
- Fix: use get_oracle_connection() instead of direct pool.acquire()
- Fix: CRM_POLITICI_PRET_ART INSERT to match actual table schema

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

api/app/templates/base.html

@@ -20,11 +20,6 @@
                     <i class="bi bi-speedometer2"></i> Dashboard
                 </a>
             </li>
-            <li class="nav-item">
-                <a class="nav-link {% block nav_sync %}{% endblock %}" href="/sync">
-                    <i class="bi bi-arrow-repeat"></i> Import Comenzi
-                </a>
-            </li>
             <li class="nav-item">
                 <a class="nav-link {% block nav_mappings %}{% endblock %}" href="/mappings">
                     <i class="bi bi-link-45deg"></i> Mapari SKU