refactor: migrar a bun:sqlite y adaptar servicio/tareas y pruebas

Co-authored-by: aider (openrouter/openai/gpt-5) <aider@aider.chat>

src/server.ts

@@ -1,4 +1,5 @@
-/// <reference types="bun-types" />
+//// <reference types="bun-types" />
+import type { Database } from 'bun:sqlite';
 import { CommandService } from './services/command';
 import { GroupSyncService } from './services/group-sync';
 import { ResponseQueue } from './services/response-queue';

src/tasks/service.ts

@@ -1,4 +1,4 @@
-import type { Database } from 'better-sqlite3';
+import type { Database } from 'bun:sqlite';
 import { db } from '../db';
 
 type CreateTaskInput = {
@@ -21,15 +21,15 @@ export class TaskService {
       const insertTask = this.dbInstance.prepare(`
         INSERT INTO tasks (description, due_date, group_id, created_by)
         VALUES (?, ?, ?, ?)
-        RETURNING id
       `);
 
-      const taskResult = insertTask.get(
+      const runResult = insertTask.run(
         task.description,
         task.due_date ?? null,
         task.group_id ?? null,
         task.created_by
-      ) as { id: number };
+      );
+      const taskId = Number((runResult as any).lastInsertRowid);
 
       if (assignments.length > 0) {
         const insertAssignment = this.dbInstance.prepare(`
@@ -42,11 +42,11 @@ export class TaskService {
         for (const a of assignments) {
           if (seen.has(a.user_id)) continue;
           seen.add(a.user_id);
-          insertAssignment.run(taskResult.id, a.user_id, a.assigned_by);
+          insertAssignment.run(taskId, a.user_id, a.assigned_by);
         }
       }
 
-      return taskResult.id;
+      return taskId;
     });
 
     return runTx();

tests/unit/tasks/service.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach, afterEach } from 'bun:test';
-import Database from 'better-sqlite3';
+import { Database } from 'bun:sqlite';
 import { initializeDatabase, ensureUserExists } from '../../../src/db';
 import { TaskService } from '../../../src/tasks/service';