feat: add Activity type system, DB migration, and self-only showActivity in sanitizeUser

- Add Activity, ActivityType, ActivityTimestamps, ActivityAssets types to shared types
- Add activity_update client event and activities field on presence_update server event
- Add userActivities to ready payload and showActivity to User/UpdateUserRequest
- Create shared activities.ts with ACTIVITY_LIMITS, ACTIVITY_PRIORITY, getPrimaryActivity
- Add show_activity column to users table (schema + migration)
- Update sanitizeUser with isSelf parameter; only include showActivity for self
- Fix .map(sanitizeUser) calls to use arrow wrapper to prevent index-as-boolean bug
- Mark auth routes (register/login) as isSelf=true since they return own user data

packages/server/src/db/migrate.ts

@@ -151,6 +151,12 @@ export function runMigrations(db: Database.Database): void {
         { name: 'password_changed_at', type: 'INTEGER' },
       ]
     },
+    {
+      name: 'users',
+      columns: [
+        { name: 'show_activity', type: 'INTEGER NOT NULL DEFAULT 1' },
+      ]
+    },
     // gif_api_key is handled by migrateRenameGifApiKey() — do NOT add it here
     // or it will race with the tenor_api_key → gif_api_key rename migration
   ];

packages/server/src/db/schema.ts

@@ -20,6 +20,7 @@ export const users = sqliteTable('users', {
   discoverable: integer('discoverable').default(1),
   profileUpdatedAt: integer('profile_updated_at'),
   passwordChangedAt: integer('password_changed_at'),
+  showActivity: integer('show_activity').notNull().default(1),
   createdAt: integer('created_at').notNull(),
 });