feat: add saved views — database table, CRUD API, migration

- New views table (id, name, filters jsonb, sort_key, is_public, creator_id)
- GET/POST/PATCH/DELETE /views endpoints
- Register views router in server

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/index.ts

@@ -12,6 +12,7 @@ import { createCustomFieldsRouter } from './routes/custom-fields.ts';
 import { createLifecyclesRouter } from './routes/lifecycles.ts';
 import { createUsersRouter } from './routes/users.ts';
 import { createTemplatesRouter } from './routes/templates.ts';
+import { createViewsRouter } from './routes/views.ts';
 
 let db: Db | null = null;
 
@@ -35,6 +36,7 @@ app.route('/custom-fields', createCustomFieldsRouter(getDb()));
 app.route('/lifecycles', createLifecyclesRouter(getDb()));
 app.route('/users', createUsersRouter(getDb()));
 app.route('/templates', createTemplatesRouter(getDb()));
+app.route('/views', createViewsRouter(getDb()));
 
 export default app;
 export { app };