fix: correct pet needs decay accumulation

[mozyonee]

Issues fixed

1. Pet needs not decaying at all

pet.needs is a Mongoose subdocument — spreading it with { ...needs } copies internal Mongoose state instead of plain values. calculateDecayedNeeds was computing decay on garbage data and writing the original unchanged values back to the DB. Fixed by extracting a plain object via PET_NEED_KEYS before passing to the function.

2. Decay intervals being silently lost

needsUpdatedAt was saved as wall-clock new Date() after each decay write, discarding the sub-interval remainder. Under normal 5s polling with any timing jitter, up to 50% of decay intervals could be lost each cycle. Fixed by snapping needsUpdatedAt to lastUpdatedAt + intervals * PET_UPDATE_INTERVAL so the remainder carries over to the next run. calculateDecayedNeeds now returns intervals to support this.

3. Verbose urgent needs check

The startExpedition urgent needs guard used 5 individual if statements. Condensed to a single PET_NEED_KEYS.some(...) call.

Test plan

• Verify pet needs decrease over time when polling /pets/:id or /pets/user
• Verify needs decay correctly after a long gap (pet not fetched for several minutes)
• Verify starting an expedition is blocked when any need is below the urgent threshold

[railway-app]

🚅 Deployed to the widgetable-pr-13 environment in widgetable

Service	Status	Web	Updated (UTC)
Server	✅ Success (View Logs)	Web	Mar 9, 2026 at 12:04 am
Client	✅ Success (View Logs)	Web	Mar 8, 2026 at 11:34 pm