feat(sprint7): Phase 1 — notifications enhancement + push infrastructure

Phase 1 (Notification Enhancement):
- Extended NotificationType enum (ADMIN_MESSAGE, INFO_BOARD_POST, FORUM_REPLY, FORUM_MENTION)
- Extended StaffPermission enum (SEND_NOTIFICATIONS, MANAGE_INFO_BOARD, MODERATE_FORUM)
- Extended AuditEventType with Sprint 7 events
- Flyway V11: notification_sends + notification_send_recipients tables
- NotificationSend + NotificationSendRecipient entities
- NotificationSendRepository + NotificationSendRecipientRepository
- Extended NotificationService with sendBroadcast() and sendToSelected()
- NotificationComposeController (POST /compose, GET /sends)
- ComposeNotificationRequest DTO

Phase 1B (Push Infrastructure):
- Flyway V12: device_tokens + notification_preferences tables
- DeviceToken entity + DevicePlatform enum
- NotificationPreference entity + NotificationChannel enum
- DeviceTokenRepository + NotificationPreferenceRepository
- DeviceRegistrationService (register/unregister/list devices, max 10 per user)
- NotificationPreferenceService (get/create defaults, update, IN_APP always on)
- NotificationDispatchService (multi-channel fan-out: WebSocket, Web Push, FCM, Email)
- WebPushSender (VAPID-based, simplified for MVP)
- FcmPushSender (graceful degradation if not configured)
- PushPayload DTO
- DeviceRegistrationController (POST/GET/DELETE /devices, GET /vapid-key)
- NotificationPreferenceController (GET/PUT /preferences)
- ConsentType extended (NOTIFICATION_PUSH, NOTIFICATION_EMAIL)
- TargetType enum (ALL, SELECTED)

Frontend:
- Updated sw.js with push event handler + notification click handler
- push-subscription.ts (subscribeToPush, unsubscribe, permission helpers)
- notification-compose.ts service (compose, sends, devices, preferences APIs)
- i18n keys (de.json + en.json) for compose, preferences, push, devices

Configuration:
- application-docker.properties: VAPID + FCM push config properties
- MemberRepository: added findAllActiveUserIds() for broadcast

cannamanage-frontend/messages/en.json

@@ -499,7 +499,52 @@
       "QUOTA_WARNING": "Quota Warning",
       "BATCH_RECALLED": "Batch Recalled",
       "DISTRIBUTION_RECORDED": "Distribution Recorded",
-      "SUBSCRIPTION_EXPIRING": "Subscription Expiring"
+      "SUBSCRIPTION_EXPIRING": "Subscription Expiring",
+      "ADMIN_MESSAGE": "Club Message",
+      "INFO_BOARD_POST": "New Announcement",
+      "FORUM_REPLY": "Forum Reply",
+      "FORUM_MENTION": "Forum Mention"
+    },
+    "compose": {
+      "title": "Compose Notification",
+      "titleField": "Title",
+      "messageField": "Message",
+      "linkField": "Link (optional)",
+      "targetAll": "All Members",
+      "targetSelected": "Selected Members",
+      "selectMembers": "Select members",
+      "send": "Send",
+      "sending": "Sending...",
+      "sent": "Notification sent to {count} members",
+      "history": "History",
+      "sentAt": "Sent at",
+      "recipients": "Recipients",
+      "readCount": "Read"
+    },
+    "preferences": {
+      "title": "Notification Settings",
+      "inApp": "In-App (always active)",
+      "email": "Email",
+      "webPush": "Browser Push Notifications",
+      "mobilePush": "Mobile Push Notifications",
+      "enabled": "Enabled",
+      "disabled": "Disabled"
+    },
+    "push": {
+      "promptTitle": "Enable Push Notifications?",
+      "promptBody": "Get notified about distributions, events, and club news directly on your device.",
+      "accept": "Enable",
+      "decline": "Not now",
+      "granted": "Push notifications enabled",
+      "denied": "Push notifications denied"
+    },
+    "devices": {
+      "title": "Registered Devices",
+      "noDevices": "No devices registered",
+      "remove": "Remove",
+      "web": "Web Browser",
+      "ios": "iPhone/iPad",
+      "android": "Android Device"
     }
   },
   "pwa": {