Show preset wish names in the current UI language

Preset wishes were created with `name: t(preset.labelKey)`, so the
translated string was persisted as the wish's name. A wish created while
the UI was Swedish stayed "Jul" in English forever -- the Swedish text
was the data, so no display-layer change could fix it.

Wish names are user-editable free text, so `name` cannot simply be
translated at render time. Migration 007 adds a nullable
`leave_wish.name_message_key` recording where a name came from: preset
wishes store the i18n key alongside the translated literal, and the UI
renders the key when present.

The key is cleared server-side the moment `name` actually changes,
compared against the stored value rather than trusting the caller, so no
client can forget to clear it and silently revert a user's own name to a
preset label.

An unknown key (a stale row, a renamed key) falls back to the stored
literal via an isTranslationKey guard, so a bad key can never crash the
page or leak a raw key to the user. Rows predating this column keep
displaying their stored name.

_FULL_SCHEMA in db/connection.py is updated in step with the migration.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RXMhc9nT6sNz1SL4j8dznL

frontend/src/types/api.ts

@@ -71,6 +71,10 @@ export interface LeaveWishCreateRequest {
   workspaceId: string
   childId?: string | null
   name: string
+  // The i18n key `name` was translated from, when created from a preset —
+  // see `LeaveWish.nameMessageKey`. `undefined`/omitted means "no key"
+  // (a free-typed name); passing `null` on an update explicitly clears it.
+  nameMessageKey?: string | null
   windowStartMonth: number
   windowStartDay: number
   windowEndMonth: number

frontend/src/types/entities.ts

@@ -33,6 +33,12 @@ export interface LeaveWish {
   workspaceId: string
   childId: string | null
   name: string
+  // i18n provenance of `name` (see backend/app/entities/leave_wish.py):
+  // the message key a preset (Sommar/Jullov/...) was created from, or
+  // `null` for a free-typed/edited name. An untyped string as it arrives —
+  // resolve display text through `resolveWishName` (src/utils/wishName.ts),
+  // never `t()` directly, since a stale/unknown key must not crash.
+  nameMessageKey: string | null
   windowStartMonth: number
   windowStartDay: number
   windowEndMonth: number