feat(clients): tiered stats overlay everywhere — Compact/Normal/Detailed on every platform

Ship the Android client's 3-tier stats-overlay semantics in every other client
(design/stats-unification.md vocabulary): Off → Compact (one line: fps · e2e ms ·
Mb/s + loss flag) → Normal (mode + e2e p50/p95 + loss counters) → Detailed
(decoder path, HDR tag, per-stage latency equation).

Apple: new StatsVerbosity in PunktfunkKit persisted under punktfunk.statsVerbosity
(migrates the legacy hudEnabled bool: explicit off → Off, else Normal). The
existing three-finger tap (TouchMouse, trackpad/pointer modes only — touch
passthrough untouched) now cycles the tiers instead of toggling, matching
Android; ⌃⌥⇧S (menu + captured-state monitor) cycles the same ladder. Tiered
StreamHUDView (compact glass pill / headline HUD / full equation HUD); the iOS
corner disconnect also shows in Compact (the pill carries no button). Tier
pickers on iOS, macOS, tvOS and the gamepad settings UI.

Session stack (Linux + Windows + Deck share punktfunk-session): shared
pf_client_core::trust::StatsVerbosity; Settings grows stats_verbosity with a
show_stats fallback, and writes keep the legacy bool in sync so pre-tier
binaries reading the same JSON agree on off vs on. Ctrl+Alt+Shift+S cycles the
tier and re-renders the OSD immediately from the last stats window; the stdout
stats: line always carries the full Detailed text so the shell status card and
scripts keep a stable shape; --stats bumps Off → Normal without demoting a
richer tier. Tier pickers in the GTK dialog, the WinUI settings page and the
console-UI settings row; shortcut copy updated (GTK shortcuts window, Windows
help, session README). The Windows legacy builtin path keeps its bool HUD.

Tests: tier migration/round-trip in trust.rs, tiered stats_text output in
pf-presenter.

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

clients/apple/Sources/PunktfunkKit/Input/TouchMouse.swift

@@ -2,7 +2,8 @@
 // touch gesture model (clients/android .../TouchInput.kt) so the two touch clients feel
 // identical. Two mouse modes share one gesture vocabulary — tap = left click · two-finger
 // tap = right click · two-finger drag = scroll · tap-then-press-and-drag = held left drag
-// (text selection / window moves) · three-finger tap = stats-HUD toggle:
+// (text selection / window moves) · three-finger tap = cycles the stats overlay tiers
+// (off → compact → normal → detailed, matching Android):
 //
 //  * trackpad (default): the cursor STAYS PUT on touch-down and moves by the finger's
 //    relative delta with mild acceleration — swipe to nudge, lift and re-swipe to walk it
@@ -164,7 +165,7 @@ final class TouchMouse {
         } else if !moved {
             switch maxFingers {
             case 3...:
-                Self.toggleHUD() // in-stream stats-overlay toggle, same as Android
+                Self.cycleStats() // in-stream stats-tier cycle, same as Android
             case 2: // two-finger tap → right click
                 send?(.mouseButton(Button.right, down: true))
                 send?(.mouseButton(Button.right, down: false))
@@ -274,12 +275,11 @@ final class TouchMouse {
         }
     }
 
-    /// Three-finger tap toggles the stats overlay — through the shared `hudEnabled` default,
-    /// which the app's HUD views observe via @AppStorage (so this needs no wiring to them).
-    private static func toggleHUD() {
-        let defaults = UserDefaults.standard
-        let on = defaults.object(forKey: DefaultsKey.hudEnabled) as? Bool ?? true
-        defaults.set(!on, forKey: DefaultsKey.hudEnabled)
+    /// Three-finger tap cycles the stats overlay tiers (off → compact → normal → detailed) —
+    /// through the shared `statsVerbosity` default, which the app's HUD views observe via
+    /// @AppStorage (so this needs no wiring to them). Same cycle as Android's triple-tap.
+    private static func cycleStats() {
+        StatsVerbosity.store(StatsVerbosity.current.next())
     }
 }
 #endif