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

backend/app/services/leave_wish_service.py

@@ -37,6 +37,7 @@ class LeaveWishService:
         target_weeks: int,
         first_year: int,
         child_id: UUID | None = None,
+        name_message_key: str | None = None,
         recurrence: str = "once",
         last_year: int | None = None,
         priority: int = 1,
@@ -65,6 +66,7 @@ class LeaveWishService:
             workspace_id=workspace_id,
             child_id=child_id,
             name=name,
+            name_message_key=name_message_key,
             window_start_month=window_start_month,
             window_start_day=window_start_day,
             window_end_month=window_end_month,
@@ -97,6 +99,7 @@ class LeaveWishService:
         leave_wish_id: UUID,
         child_id: UUID | None = None,
         name: str | None = None,
+        name_message_key: str | None = None,
         window_start_month: int | None = None,
         window_start_day: int | None = None,
         window_end_month: int | None = None,
@@ -114,21 +117,35 @@ class LeaveWishService:
         _clear_last_year: bool = False,
         _clear_parent_personal_data_uuid: bool = False,
         _clear_goal_override: bool = False,
+        _clear_name_message_key: bool = False,
     ) -> LeaveWish:
         """Partial update — only non-None fields are applied.
 
         `_clear_*` flags exist because a nullable field's "no change" and
         "set to None" both look like `None` on the wire; the router passes
         them based on whether the field was present in the request payload.
+
+        `name_message_key` is additionally enforced here rather than left to
+        callers: whenever `name` actually changes, the key is force-cleared
+        regardless of what was passed for it, since a caller (frontend bug,
+        future API client, ...) forgetting to clear it would silently make a
+        user's edited name revert to a stale preset label.
         """
         entity = await self.get(leave_wish_id)
+        original_name = entity.name
 
         if _clear_child_id:
             entity.child_id = None
         elif child_id is not None:
             entity.child_id = child_id
+        if _clear_name_message_key:
+            entity.name_message_key = None
+        elif name_message_key is not None:
+            entity.name_message_key = name_message_key
         if name is not None:
             entity.name = name
+            if name != original_name:
+                entity.name_message_key = None
         if window_start_month is not None:
             entity.window_start_month = window_start_month
         if window_start_day is not None: