fix: sub-day deadline precision in get_campaign_status

[morelucks]

Summary

This PR addresses issue #45 where sub-day deadline values for campaigns are truncated to 0 by the integer division (end_time - now) / 86_400. Rather than applying a breaking change to existing days_remaining semantics, we implemented Option A (additive) which keeps backward compatibility while introducing higher granularity for clients (e.g., dashboards and indexers).

Proposed Changes

1. Schema Update (campaign/src/types.rs):
   • Added hours_remaining: u32 to the CampaignStatusResponse struct.
2. Logic Implementation (campaign/src/contract.rs):
   • Refactored get_campaign_status to compute both days_remaining and hours_remaining using the time delta.
   • For past/expired campaigns, hours_remaining is clamped to 0.
3. Unit Tests & Ledger Snapshots (campaign/src/test/get_campaign_status_tests.rs):
   • Updated existing assertions to verify the newly added field.
   • Added calculates_subday_remaining to verify that active campaigns with less than 24 hours remaining return the correct number of hours.
   • Added calculates_past_subday_remaining to verify that campaigns past their deadlines return 0 hours.
   • Automatically regenerated ledger snapshots under campaign/test_snapshots/test/get_campaign_status_tests/.

Closes #45

[Alqku]

Nice granularity improvement addressing the sub-day truncation in #45. One heads-up though: adding hours_remaining to CampaignStatusResponse changes the return-shape contract ABI of get_campaign_status — any dApp, indexer, or downstream tooling fetching that struct will see a different layout. Options: (a) ship this deliberately as a breaking ABI change and bump the contract version explicitly, or (b) expose hours in a separate get_campaign_hours_remaining view (or as a tuple) to keep the existing struct shape. Either way let us coordinate the deploy. Looking forward to a follow-up.

[Alqku]

Hey @morelucks 👋 — the sub-day deadline fix for #45 looks correct. Unfortunately I don't see any CI check results on this PR. Could you rebase onto the latest main (or push an empty commit) to retrigger the workflow? Once the fmt/clippy/test/wasm jobs come back green I'll merge this right away 🚀