feat(user): User Information Delete Method

[zigzagdev]

Summary

• Add deleteUser(id) to the user API client (DELETE /api/v1/users/:id, 204 No Content — no response body, Promise<void>)
• No mapper stage: deletion only ever needs the target id, there's no form-values object with a different shape to convert (see feat: 削除対象をAPIリクエストへ変換するmapperを追加 #424, closed as not needed)
• Add useDeleteUser hook: manages done/isLoading/error, aborts the in-flight request on resubmit/unmount, matching useCreateUser/useUpdateUser
• Wire delete into the existing /users/:id page instead of a separate route: UserGetContainer drives useDeleteUser and navigates to /heritages once deletion completes
• UserProfileView gains a "Delete User" button that opens a confirmation dialog (MUI Dialog); confirming calls the delete, cancelling is a no-op; shows an error panel on failure
• Add userDeleteButton/userDeleteConfirmTitle/userDeleteConfirmMessage/userDeleteError i18n keys (en/ja)

Related

Closes #422

Test plan

• npx tsc --noEmit
• npx jest src/app/features/user
• npx prettier --check on the touched files

[zigzagdev]

Ok