fix(apple): recover dropped macOS client features lost in the W7/W8 refactor

The W7/W8 client refactor (extracting FullscreenController/ApprovalRequest out of
ContentView, splitting Settings) landed the DefaultsKeys + scaffolding but dropped
the feature WIRING, which was uncommitted WIP shelved in a stash during the
16:28 clipboard/v4 reconcile. Recovered from that stash (+ its untracked-files
parent for the whole new ModifierLayout.swift) and re-ported onto the refactored
tree:

- invertScroll: applied in InputCapture.sendScroll (the one scroll sink) + Settings toggle
- modifierLayout (Cmd/Option switch): restored ModifierLayout.swift enum + KeyMaps
  .applyModifierLayout + InputCapture.emitKey wire-boundary + Settings picker
- fullscreen shortcut (Ctrl+Cmd+F): InputCapture ⌃⌘F interception + onToggleFullscreen
  + StreamView wiring + Stream-menu item (the .punktfunkToggleFullscreen sink +
  FullscreenController observer already survived on main)
- render scale: Settings picker + MatchWindowFollower renderScale/maxDimension
  application + StreamView/StreamViewIOS plumbing (RenderScale.swift already on main)

StreamCommands re-ported by hand (the stash hunk deleted the since-landed clipboard
item — kept it, added the fullscreen item alongside). Recovered ModifierLayout +
RenderScale tests. swift build green; 15 tests pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/apple/Sources/PunktfunkClient/Session/StreamCommands.swift

@@ -72,6 +72,14 @@ struct StreamCommands: Commands {
             }
             .keyboardShortcut("c", modifiers: [.control, .option, .shift])
             .disabled(session?.isStreaming != true || session?.clipboardAvailable != true)
+            // Toggle the window's fullscreen. ⌃⌘F is the macOS-standard fullscreen combo; here it's
+            // explicit so it's discoverable AND survives capture — while streaming the stream view
+            // swallows keys, so InputCapture's monitor detects the same combo and posts the same
+            // notification the key window's FullscreenController observes.
+            Button("Toggle Fullscreen") {
+                NotificationCenter.default.post(name: .punktfunkToggleFullscreen, object: nil)
+            }
+            .keyboardShortcut("f", modifiers: [.control, .command])
             #endif
             Divider()
             Button("Disconnect") { session?.disconnect() }