De-hardcode ticket URL and cluster name; improve diagnostic polling UX

app.py:
- Context processor injects config.ticket_api.web_url into all templates
  (falls back to 'http://t.lotusguild.org/ticket/' if not set in config)

templates/base.html:
- Inject GANDALF_CONFIG JS global with ticket_web_url before app.js loads

static/app.js:
- Use GANDALF_CONFIG.ticket_web_url instead of hardcoded domain

templates/index.html:
- Use {{ config.ticket_api.web_url }} Jinja var instead of hardcoded domain

monitor.py:
- CLUSTER_NAME constant kept as default; NetworkMonitor now reads cluster_name
  from config monitor.cluster_name, falling back to the constant
- All CLUSTER_NAME references inside class methods replaced with self.cluster_name

templates/inspector.html:
- pollDiagnostic() .catch() now clears interval and shows error message instead
  of silently ignoring network failures during active polling

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

app.py

@@ -29,6 +29,19 @@ app = Flask(__name__)
 
 _cfg = None
 
+
+@app.context_processor
+def inject_config():
+    """Inject safe config values into all templates."""
+    cfg = _config()
+    return {
+        'config': {
+            'ticket_api': {
+                'web_url': cfg.get('ticket_api', {}).get('web_url', 'http://t.lotusguild.org/ticket/'),
+            }
+        }
+    }
+
 # In-memory diagnostic job store { job_id: { status, result, created_at } }
 _diag_jobs: dict = {}
 _diag_lock = threading.Lock()