feat: add type column to dm_messages for system message support

Adds a `type` column (TEXT NOT NULL DEFAULT 'user') to the dm_messages
table via schema, migration, and type definition. Updates
buildDmMessageWithUser and the inline replyTo builder in the GET
messages handler to include the field in all DM message responses.

packages/server/src/db/migrate.ts

@@ -196,6 +196,12 @@ export function runMigrations(db: Database.Database): void {
         { name: 'encryption_version', type: 'INTEGER DEFAULT 0' },
       ]
     },
+    {
+      name: 'dm_messages',
+      columns: [
+        { name: 'type', type: "TEXT NOT NULL DEFAULT 'user'" },
+      ]
+    },
     {
       name: 'attachments',
       columns: [

packages/server/src/db/schema.ts

@@ -140,6 +140,7 @@ export const dmMessages = sqliteTable('dm_messages', {
   userId: text('user_id').notNull().references(() => users.id),
   replyToId: text('reply_to_id'),
   content: text('content'),
+  type: text('type').notNull().default('user'),
   editedAt: integer('edited_at'),
   sourceInstance: text('source_instance'),
   sourceMessageId: text('source_message_id'),

packages/server/src/routes/dm.ts

@@ -90,6 +90,7 @@ export function buildDmMessageWithUser(
     userId: message.userId,
     replyToId: message.replyToId,
     content: message.content,
+    type: (message.type ?? 'user') as 'user' | 'system',
     editedAt: message.editedAt,
     createdAt: message.createdAt,
     sourceMessageId: message.sourceMessageId ?? null,
@@ -1270,6 +1271,7 @@ export async function dmRoutes(app: FastifyInstance): Promise<void> {
           userId: rm.userId,
           replyToId: rm.replyToId,
           content: rm.content,
+          type: (rm.type ?? 'user') as 'user' | 'system',
           editedAt: rm.editedAt,
           createdAt: rm.createdAt,
           user: sanitizeUser(rUser),

packages/shared/src/types.ts

@@ -281,6 +281,7 @@ export interface DmMessage {
   dmChannelId: string;
   userId: string;
   content: string | null;
+  type?: 'user' | 'system';
   createdAt: number;
   // Compatibility fields
   channelId?: string;