Story-1042: Forum settings functional + app-wide button motion system

sequenceDiagram
  autonumber
  participant user as User
  participant shell as SettingsShell
  participant motion as MotionProvider
  participant api as Internal API
  user->>shell: open forums settings
  motion->>motion: init with reducedMotion=user
  shell->>user: header + toolbar + search render
  user->>shell: pick segment (All / Active / Archived)
  shell->>user: AnimatedList rows — firm editable, system read-only
  user-->>api: edit firm row → POST /api/internal/forums
  api-->>user: row animates exit, list reorders