fix(kiloclaw): remove delayed-billing start date that causes Stripe checkout failures

[jeanduplessis]

Summary

• Removes the STRIPE_KILOCLAW_BILLING_START env var and the trial_end logic in checkout session creation. This mechanism deferred billing for pre-launch subscribers until March 23, but Stripe requires trial_end to be at least 48 hours in the future — causing checkout failures for users as we approached that date.
• New subscriptions now always bill immediately. Pre-launch subscriptions that already have a trial_end are still handled correctly by the existing trialing→active status mapping.
• Updates the billing spec to remove the configurable billing start date rules and documents the change in the changelog.

Verification

• pnpm typecheck — passes across all workspace projects
• pnpm test -- src/routers/kiloclaw-billing-router.test.ts — 25/25 tests pass
• Pre-push hooks (format, lint, typecheck) all pass

Visual Changes

N/A

Reviewer Notes

• .env.local still contains STRIPE_KILOCLAW_BILLING_START="2026-03-23" — should be removed manually (file edit was blocked by repo rules). The production env var should also be removed.
• The trialing→active mapping in stripe-handlers.ts is now only needed for legacy pre-launch subs. A TODO was added to remove it after ~2026-03-23 when those subscriptions transition.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (6 files)

• .env.test
• .specs/kiloclaw-billing.md
• src/lib/config.server.ts
• src/lib/kiloclaw/stripe-handlers.ts
• src/routers/kiloclaw-billing-router.test.ts
• src/routers/kiloclaw-router.ts

---

_{Reviewed by gpt-5.4-20260305 · 246,221 tokens}