feat: notifications, audit logging, and admin improvements

- Add centralized notification service with webhook (Discord/Slack) and
  email (SMTP) support, triggered for trip invites, booking changes,
  collab messages, and trip reminders
- Webhook sends one message per event (group channel); email sends
  individually per trip member, excluding the actor
- Discord invite notifications now include the invited user's name
- Add LOG_LEVEL env var (info/debug) controlling console and file output
- INFO logs show user email, action, and IP for audit events; errors
  for HTTP requests
- DEBUG logs show every request with full body/query (passwords redacted),
  audit details, notification params, and webhook payloads
- Add persistent trek.log file logging with 10MB rotation (5 files)
  in /app/data/logs/
- Color-coded log levels in Docker console output
- Timestamps without timezone name (user sets TZ via Docker)
- Add Test Webhook and Save buttons to admin notification settings
- Move notification event toggles to admin panel
- Add daily trip reminder scheduler (9 AM, timezone-aware)
- Wire up booking create/update/delete and collab message notifications
- Add i18n keys for notification UI across all 13 languages

Made-with: Cursor

client/src/components/Admin/AuditLogPanel.tsx

@@ -15,7 +15,11 @@ interface AuditEntry {
   ip: string | null
 }
 
-export default function AuditLogPanel(): React.ReactElement {
+interface AuditLogPanelProps {
+  serverTimezone?: string
+}
+
+export default function AuditLogPanel({ serverTimezone }: AuditLogPanelProps): React.ReactElement {
   const { t, locale } = useTranslation()
   const [entries, setEntries] = useState<AuditEntry[]>([])
   const [total, setTotal] = useState(0)
@@ -66,9 +70,10 @@ export default function AuditLogPanel(): React.ReactElement {
 
   const fmtTime = (iso: string) => {
     try {
-      return new Date(iso).toLocaleString(locale, {
+      return new Date(iso.endsWith('Z') ? iso : iso + 'Z').toLocaleString(locale, {
         dateStyle: 'short',
         timeStyle: 'medium',
+        timeZone: serverTimezone || undefined,
       })
     } catch {
       return iso