Inventory polish: smaller phone/notebook, phone higher, auto-open, exit to board

The phone and notebook render a bit smaller; the phone sits higher on screen;
in-game the handset opens automatically (session mode); and the tool view
gains an EXIT ✕ that closes the inventory straight back to the board.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/phone.tsx

@@ -269,7 +269,7 @@ function PhoneScreen({ visible, mode, dialed, callee }: { visible: boolean; mode
 export type PhoneSession = { playthroughId: string; onConnect: () => void }
 
 export function PhonePreview({ session }: { session?: PhoneSession } = {}) {
-  const [open, setOpen] = useState(false)
+  const [open, setOpen] = useState(Boolean(session)) // in-game the handset opens on its own
   const [screenOn, setScreenOn] = useState(false)
   const [mode, setMode] = useState<Mode>('home')
   const [dialed, setDialed] = useState('')