Fix global timezone on ADS-B dashboard and harden VDL2 correlation

Timezone fixes:
- Add utils.js (InterceptTime) to adsb_dashboard.html — was completely
  missing, causing all times to fall back to UTC regardless of setting
- Register onChange listener in nav.html so clock updates instantly
  when timezone/format is changed in Settings
- Initialize timezone/format dropdowns on ADS-B dashboard page load
- Browser-verified: ET/12h ↔ UTC/24h switches instantly on ADS-B page

VDL2 correlation fix:
- Force ICAO hex to uppercase when promoting from VDL2 src.addr (dumpvdl2
  may output lowercase, ADS-B stores uppercase — case mismatch prevented
  correlator from matching)
- Move ICAO/addr promotion before ACARS field extraction so even
  non-ACARS VDL2 frames (XID, connection mgmt) get correlated

Auth:
- Add INTERCEPT_DISABLE_AUTH env var to skip login for local/dev use
- Configurable via docker-compose.yml environment

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app.py

@@ -423,6 +423,11 @@ def get_sdr_device_status() -> dict[str, str]:
 
 @app.before_request
 def require_login():
+    # Skip auth entirely when INTERCEPT_DISABLE_AUTH is set
+    if os.environ.get('INTERCEPT_DISABLE_AUTH', '').lower() in ('1', 'true', 'yes'):
+        session['logged_in'] = True
+        return None
+
     # Routes that don't require login (to avoid infinite redirect loop)
     allowed_routes = ['login', 'static', 'favicon', 'health', 'health_check']
 
@@ -478,15 +483,15 @@ def login():
 
     return render_template('login.html', version=VERSION)
 
-@app.route('/')
-def index() -> str:
-    if request.args.get('mode') == 'satellite':
-        return redirect(url_for('satellite.satellite_dashboard'))
-
-    tools = {
-        'rtl_fm': check_tool('rtl_fm'),
-        'multimon': check_tool('multimon-ng'),
-        'rtl_433': check_tool('rtl_433'),
+@app.route('/')
+def index() -> str:
+    if request.args.get('mode') == 'satellite':
+        return redirect(url_for('satellite.satellite_dashboard'))
+
+    tools = {
+        'rtl_fm': check_tool('rtl_fm'),
+        'multimon': check_tool('multimon-ng'),
+        'rtl_433': check_tool('rtl_433'),
         'rtlamr': check_tool('rtlamr')
     }
     devices = [d.to_dict() for d in SDRFactory.detect_devices()]