Refactor: Optimize updateAllUserStatus Cron Job Query to Prevent Full Collection Scan

[Soumava-221B]

Description

The updateAllUserStatus function runs as a cron job to transition users' statuses. Currently, the query retrieves every user status document where a future status state exists:

const userStatusDocs = await userStatusModel
  .where("futureStatus.state", "in", ["ACTIVE", "IDLE", "OOO"])
  .get();

This fetches all future status documents, regardless of whether their transition start date has arrived. We should add a timestamp-based filter to retrieve only the documents that actually need to transition:

const userStatusDocs = await userStatusModel
  .where("futureStatus.state", "in", ["ACTIVE", "IDLE", "OOO"])
  .where("futureStatus.from", "<=", Date.now())
  .get();

(Note: A composite index on futureStatus.state and futureStatus.from will be required).

Why do we need to fix this?

• Cost Efficiency: Currently, we pay for Firestore reads on every single future status document, even if they aren't scheduled to change for weeks. Adding this filter reduces reads to only the documents transitioning today.
• Performance: Prevents iterating over and processing thousands of irrelevant documents in memory, reducing the memory footprint of the cron service.
• Scalability: Prevents the cron job from slowing down as the community user base and scheduled statuses grow over time.