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

Dockerfile

@@ -1,4 +1,4 @@
-# Stage 1: React Client bauen
+# Stage 1: Build React client
 FROM node:22-alpine AS client-builder
 WORKDIR /app/client
 COPY client/package*.json ./
@@ -6,34 +6,25 @@ RUN npm ci
 COPY client/ ./
 RUN npm run build
 
-# Stage 2: Produktions-Server
+# Stage 2: Production server
 FROM node:22-alpine
 
 WORKDIR /app
 
-# Timezone support + Server-Dependencies (better-sqlite3 braucht Build-Tools)
+# Timezone support + native deps (better-sqlite3 needs build tools)
 COPY server/package*.json ./
-RUN apk add --no-cache tzdata su-exec python3 make g++ && \
+RUN apk add --no-cache tzdata dumb-init su-exec python3 make g++ && \
     npm ci --production && \
     apk del python3 make g++
 
-# Server-Code kopieren
 COPY server/ ./
-
-# Gebauten Client kopieren
 COPY --from=client-builder /app/client/dist ./public
-
-# Fonts für PDF-Export kopieren
 COPY --from=client-builder /app/client/public/fonts ./public/fonts
 
-# Verzeichnisse erstellen + Symlink für Abwärtskompatibilität (alte docker-compose mounten nach /app/server/uploads)
-RUN mkdir -p /app/data /app/uploads/files /app/uploads/covers /app/uploads/avatars /app/uploads/photos && \
-    mkdir -p /app/server && ln -s /app/uploads /app/server/uploads && ln -s /app/data /app/server/data
+RUN mkdir -p /app/data/logs /app/uploads/files /app/uploads/covers /app/uploads/avatars /app/uploads/photos && \
+    mkdir -p /app/server && ln -s /app/uploads /app/server/uploads && ln -s /app/data /app/server/data && \
+    chown -R node:node /app
 
-# Fix permissions on mounted volumes at runtime and run as node user
-RUN chown -R node:node /app
-
-# Umgebung setzen
 ENV NODE_ENV=production
 ENV PORT=3000
 
@@ -42,5 +33,5 @@ EXPOSE 3000
 HEALTHCHECK --interval=30s --timeout=5s --start-period=15s --retries=3 \
   CMD wget -qO- http://localhost:3000/api/health || exit 1
 
-# Entrypoint: fix volume permissions then start as node
-CMD ["sh", "-c", "chown -R node:node /app/data /app/uploads 2>/dev/null; exec su-exec node node --import tsx src/index.ts"]
+ENTRYPOINT ["dumb-init", "--"]
+CMD ["sh", "-c", "chown -R node:node /app/data /app/uploads 2>/dev/null || true; exec su-exec node node --import tsx src/index.ts"]