Continues the incremental server TS migration (after utils/*.mts and
paymentValidation.cts): converts 10 services to .cts (CommonJS TypeScript,
run natively via Node type-stripping — no build step), type-checked by
tsconfig.server.json.
Migrated: totpService, amountSuggestionService, encryptionService,
paymentAccountingService, statusService, aprService, driftService,
analyticsService, spendingService, billMerchantRuleService.
- types/db.d.ts: shared minimal better-sqlite3 Db/Statement types (the lib
ships none), reused across the migrated modules.
- Every require of a migrated service updated to the explicit .cts extension
(extensionless require does not resolve .cts) across routes / services /
db migrations / server.js / workers / tests — require-only changes.
- package.json: check:server find pattern now includes *.cts (it silently
skipped .cts before, so paymentValidation.cts had no node --check gate).
Behavior-preserving (types only). Verified: typecheck:server 0,
check:server 0, full server suite 226/226, real boot → /api/health 200.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
The payoff simulation reported months_to_freedom by taking Math.max over each
debt's payoff month — but a debt whose minimum never overcomes its interest (and
that the rolling snowball can't cover) never reaches $0, so its "never" counted
as 0 and the projection showed the OTHER debts' last month as the freedom date.
Now months_to_freedom/payoff_date are null when any active debt never clears, the
result is flagged capped, and each such debt is marked never_paid
(services/snowballService.js + the same guard in aprService calculateMinimumOnly).
Also adds tests/snowballMath.test.js (12) — the debt-payoff engine had zero
coverage. Hand-calculated examples for amortization (0% + 12% APR), snowball
rolling, avalanche vs snowball interest, skip reasons, APR snapshot, and the
unpayable-debt edge. Server suite 151 pass.
Co-Authored-By: Claude Opus 4.8 <[email protected]>