Add partial index on tools for active_subscription filtering

[devin-ai-integration]

Summary

Adds a Supabase migration that creates a partial B-tree index on tools(billing_cycle) WHERE active_subscription = true.

Analysis performed: The active_subscription column is used as a filter predicate in three client-side computed selectors (totalMonthlyCost, totalAnnualCost, renewingWithin30Days), all of which filter for active_subscription === true and then branch on billing_cycle. The partial index targets this pattern and keeps the index footprint small by only including rows with active subscriptions.

bill_day was intentionally not indexed — it is only consumed by the nextRenewalDate() date computation utility and never appears as a filter, join, or sort predicate.

Important caveat: Currently, fetchTools loads all rows via select('*').order('name') and all filtering happens client-side in JS. This index is forward-looking — it won't be exercised until those selectors are refactored into server-side queries (e.g. .eq('active_subscription', true)).

Review & Testing Checklist for Human

• Confirm the index is actually useful for your roadmap — no current Supabase query filters on active_subscription or billing_cycle server-side. If you don't plan to push these filters to the DB, this index adds write overhead with no read benefit.
• Verify the partial index design (ON tools(billing_cycle) WHERE active_subscription = true) matches the query patterns you intend to support. If you'd rather filter/sort by a different column (e.g. cost, renewal_date), the indexed column should change.
• Confirm skipping an index on bill_day is acceptable for your use case.

Notes

• The migration uses CREATE INDEX IF NOT EXISTS, so it is idempotent and safe to re-run.
• The migration filename (20260415_...) follows the existing naming convention in supabase/migrations/.

Link to Devin session: https://app.devin.ai/sessions/c463c41903f2427ebc930a895dc4e7ad
Requested by: @alecvdp

---

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 1 additional finding.