fix(tasks): Fix missing column errors in task queries

- Change 'active' to 'is_active' in states table query (store-discovery.ts)
- Remove non-existent 'active' column check from worker_tasks query (task-service.ts)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/tasks/handlers/store-discovery.ts

@@ -25,7 +25,7 @@ export async function handleStoreDiscovery(ctx: TaskContext): Promise<TaskResult
   try {
     // Get states to discover
     const statesResult = await pool.query(`
-      SELECT code FROM states WHERE active = true ORDER BY code
+      SELECT code FROM states WHERE is_active = true ORDER BY code
     `);
     const stateCodes = statesResult.rows.map(r => r.code);