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/Support/StatsVerbosity.swift

@@ -0,0 +1,58 @@
+// The stats overlay's verbosity tier — a port of the Android client's 3-tier overlay semantics
+// so the two clients feel identical: Off → Compact (one-line pill) → Normal (headline stats) →
+// Detailed (plus the latency stage equation). Persisted under `DefaultsKey.statsVerbosity`;
+// the in-stream cycle surfaces (⌃⌥⇧S, the three-finger tap) advance it with
+// `store(current.next())`, and every UI reader observes the same default via @AppStorage.
+//
+// Lives in PunktfunkKit (not the app) because the kit's input paths (TouchMouse's three-finger
+// tap, InputCapture's captured-state ⌃⌥⇧S) cycle it directly.
+
+import Foundation
+
+/// How much of the streaming statistics overlay to show. The raw values are stable on disk —
+/// rename the cases freely, never the strings.
+public enum StatsVerbosity: String, CaseIterable, Sendable {
+    case off, compact, normal, detailed
+
+    /// User-facing tier label (Settings pickers, the gamepad settings row).
+    public var label: String {
+        switch self {
+        case .off: return "Off"
+        case .compact: return "Compact"
+        case .normal: return "Normal"
+        case .detailed: return "Detailed"
+        }
+    }
+
+    /// The next tier in the cycle: off → compact → normal → detailed → off (wrapping) —
+    /// the ⌃⌥⇧S / three-finger-tap order, same as Android.
+    public func next() -> StatsVerbosity {
+        switch self {
+        case .off: return .compact
+        case .compact: return .normal
+        case .normal: return .detailed
+        case .detailed: return .off
+        }
+    }
+
+    /// The persisted tier. When `statsVerbosity` has never been written, migrates from the
+    /// legacy `hudEnabled` bool the pre-tiered clients stored: absent-or-true → `.normal`
+    /// (the old "on" look minus the equation lines), explicit false → `.off`.
+    public static var current: StatsVerbosity {
+        let defaults = UserDefaults.standard
+        if let raw = defaults.string(forKey: DefaultsKey.statsVerbosity),
+           let tier = StatsVerbosity(rawValue: raw) {
+            return tier
+        }
+        if let legacy = defaults.object(forKey: DefaultsKey.hudEnabled) as? Bool, !legacy {
+            return .off
+        }
+        return .normal
+    }
+
+    /// Persist a tier (the cycle surfaces write through here; the Settings pickers write the
+    /// same key via @AppStorage).
+    public static func store(_ tier: StatsVerbosity) {
+        UserDefaults.standard.set(tier.rawValue, forKey: DefaultsKey.statsVerbosity)
+    }
+}