## Why merge this
Production bug
**[PHP-LARAVEL-1B](https://whisper-money.sentry.io/issues/PHP-LARAVEL-1B)**
— `/budgets/{budget}` throws a 500 (`UniqueConstraintViolationException`
on `budget_periods_budget_id_start_date_unique`) for the affected user.
Page is unusable for them until fixed.
## Root cause
The Custom period type let users create budgets with arbitrary
`period_duration`. Combined with `calculatePeriodDates()`'s day-of-month
snap (`startDate->day(period_start_day)`), short durations produced
periods where `end_date == start_date == period_start_day`. On the next
visit after that day, regeneration computed a new period whose start
snapped backward to the same day → unique key collision.
Concrete trace from the Sentry event:
- Budget: `Seguro de Salud`, `period_type=custom, period_duration=1,
period_start_day=1`, created `2026-05-05`.
- Initial period created at budget creation: `start=2026-05-01,
end=2026-05-01` (already 4 days stale because Custom snapped
`now()=05-05` back to day 1, then `addDays(1).subDay()` produced same
date).
- Today `05-05` → `getCurrentPeriod()` returns null → `generatePeriod()`
snaps back to `05-01` again → `INSERT (budget_id, 05-01)` → 1062.
Verified in prod DB: this is the **only** budget in the entire database
with `period_type='custom'` and the only period row with `end_date <=
start_date`.
## Fix
Custom is the only period type that exposes this snap-back collision
(Monthly/Weekly/Biweekly all use a self-consistent advance). It also has
no defensible UX — every legitimate use case is covered by
Monthly/Weekly/Biweekly. So we remove it end-to-end:
- `BudgetPeriodType::Custom` enum case dropped.
- `BudgetPeriodService`: Custom branches removed from
`calculatePeriodDates()` and `calculateNextPeriodStartDate()`.
- `Budget` model: `period_duration` removed from `$fillable` and
`casts()`.
- `StoreBudgetRequest` / `UpdateBudgetRequest`: `period_duration` rule
removed.
- `BudgetController`: `period_duration` no longer passed in
store/update.
- Create + edit budget dialogs: Custom option and `period_duration`
input removed.
- `ResetDemoAccountCommand`: Custom switch case removed.
- `BudgetFactory`: `custom()` state and `period_duration` default
removed.
- `types/budget.ts`: `'custom'` removed from `BUDGET_PERIOD_TYPES` and
`Budget.period_duration` field dropped.
- Migration `2026_05_05_132023_convert_custom_budgets_to_monthly`:
rewrites any existing `custom` rows to `monthly` with
`period_duration=null, period_start_day=1` so the dropped enum case
can't crash on hydration.
Period generation logic for Monthly/Weekly/Biweekly is **unchanged**.
## Manual prod cleanup (separate, after merge)
The single buggy budget in prod will be deleted manually:
```sql
DELETE FROM budget_periods WHERE id = '019df7fd-6073-731b-9c08-f3723515292b';
DELETE FROM budgets WHERE id = '019df7fd-6071-7219-b190-ece22ccdb63f';
```
## Tests
`tests/Feature/BudgetPeriodServiceTest.php` covers Monthly + Weekly
advance and Monthly first-period generation. Existing
`BudgetPeriodDateTest` unaffected.
## Risk
- `period_duration` column kept in DB (nullable) to avoid data loss; no
migration needed.
- Migration ensures any environment with `period_type='custom'` rows is
converted before the enum case is removed, preventing hydration errors.
- No customers actively rely on Custom: prod query confirmed only the
single broken budget uses it, and that one is being deleted.
Fixes PHP-LARAVEL-1B