## What
Standardizes how models are serialized across web, API, and Sync
responses by relying on Eloquent `$hidden` + accessors on the models
themselves, instead of ad-hoc `select` scopes and per-controller field
picking.
Touches 9 models (`Account`, `Bank`, `Budget`, `Category`, `Label`,
`LoanDetail`, `RealEstateDetail`, `Transaction`, plus pivot hiding) and
the controllers/middleware that consumed the old ad-hoc shapes.
## Why
- Single source of truth for response shape lives on the model, aligned
with Wayfinder model typegen.
- Removes duplicated field-selection logic scattered across controllers.
- Continues the duplication-removal PR series (#475–#483).
## How
- Hide internal columns and pivots via `$hidden`; expose computed fields
via accessors.
- Controllers return full models / load full relations rather than
hand-picked columns.
- `HandleInertiaRequests` slimmed down to match.
## Notes for reviewers
- Per-commit breakdown: each model standardized in its own commit for
easy review.
- Tests added/updated for each model to assert the serialized shape
(hidden columns absent, relations present).
- Full suite: 1382 passed / 1 skipped / 0 failed. `pint` clean.
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