Add messages table for AI (bot + TMA)

Create messages table in runSchemaMigrations with id, created_at, user_telegram (FK to users), thread_id, type (bot|app), role (user|assistant|system), content, telegram_update_id (nullable). Add index for thread history (user_telegram, thread_id, type, created_at) and partial unique index for bot deduplication (user_telegram, thread_id, type, telegram_update_id) where telegram_update_id IS NOT NULL. Implements plan in app/database/plan.md.

Made-with: Cursor

Author: anriltine

app/database/start.ts

@@ -79,6 +79,31 @@ async function runSchemaMigrations() {
     CREATE INDEX IF NOT EXISTS idx_pending_tx_status
       ON pending_transactions(status);
   `;
+
+  // messages table (AI: bot + TMA)
+  await sql`
+    CREATE TABLE IF NOT EXISTS messages (
+      id                  BIGSERIAL PRIMARY KEY,
+      created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+      user_telegram       TEXT NOT NULL REFERENCES users(telegram_username),
+      thread_id           BIGINT NOT NULL,
+      type                TEXT NOT NULL CHECK (type IN ('bot', 'app')),
+      role                TEXT NOT NULL CHECK (role IN ('user', 'assistant', 'system')),
+      content             TEXT,
+      telegram_update_id  BIGINT
+    );
+  `;
+
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_messages_thread
+      ON messages(user_telegram, thread_id, type, created_at);
+  `;
+
+  await sql`
+    CREATE UNIQUE INDEX IF NOT EXISTS idx_messages_bot_update_id
+      ON messages(user_telegram, thread_id, type, telegram_update_id)
+      WHERE telegram_update_id IS NOT NULL;
+  `;
 }
 
 let schemaInitPromise: Promise<void> | null = null;