fix(salary): one save per surface on the employee form (#1623)

* fix(salary): one save per surface on the employee form

The employee edit page stacked two competing saves: the opening-balances
Card ended in "Spara ingaende saldon" and the page ended in "Spara
andringar" 80px below, with no visible boundary between their scopes.
Worse, both self-saving panels lived INSIDE the page <form> and shadcn
Button sets no default type, so every panel button (save opening
balances, add/remove benefit) implicitly submitted the outer form too,
firing the full employee PATCH alongside the panel's own request.

Restructure so each surface owns exactly one save:

- The employee <form> now closes right after the Bank card, with
  Avbryt + "Spara andringar" directly under the fields it actually saves.
- Formaner and Ingaende saldon move below the form into a "Sparas
  separat" section (uppercase kicker + one-line scope hint) so the page
  save structurally cannot include them and their buttons can no longer
  leak submits into the employee form.
- OpeningBalancesPanel becomes its own <form>: Enter saves the panel,
  and the save button enables only when its fields are actually dirty
  (fingerprint of loaded values, reset on successful save).
- EmployeeBenefitsPanel buttons get explicit type="button".

New strings in both messages/sv.json and messages/en.json.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(salary): release the loading skeleton when the balances fetch fails

CodeRabbit on #1623: a rejected fetch or JSON parse skipped the
setLoading(false) line, holding the skeleton forever. The load now
wraps in try/finally; a failed load falls back to the empty form.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

messages/en.json

@@ -6750,6 +6750,8 @@
     "detail_f_skatt_verified": "F-skatt verified: {date}",
     "detail_vacation_none_hint": "No accrual to 2920 is booked. Use if vacation is included in the monthly salary — common for owners who are the only employee.",
     "detail_save_changes": "Save changes",
+    "detail_self_saving_heading": "Saved separately",
+    "detail_self_saving_hint": "Benefits and opening balances are saved directly in each section and are not included in Save changes above.",
     "tax_title": "Tax",
     "tax_form_label": "Tax status",
     "tax_form_tooltip": "A-skatt: you withhold preliminary tax according to the tax table (skattetabell). F-skatt/FA-skatt: the person handles their own tax — no tax is withheld.",

messages/sv.json

@@ -6750,6 +6750,8 @@
     "detail_f_skatt_verified": "F-skatt verifierad: {date}",
     "detail_vacation_none_hint": "Ingen avsättning till 2920 bokas. Använd om semester ingår i månadslönen — vanligt för ägare som är enda anställd.",
     "detail_save_changes": "Spara ändringar",
+    "detail_self_saving_heading": "Sparas separat",
+    "detail_self_saving_hint": "Förmåner och ingående saldon sparas direkt i respektive sektion och ingår inte i Spara ändringar ovan.",
     "tax_title": "Skatt",
     "tax_form_label": "Skatteform",
     "tax_form_tooltip": "A-skatt: du drar preliminärskatt enligt skattetabell. F-skatt/FA-skatt: personen sköter sin egen skatt — inget skatteavdrag görs.",