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/session/README.md

@@ -21,7 +21,8 @@ Reads the same identity / known-hosts / settings stores as the desktop client
 connects to a host it has no pinned fingerprint for (`--fp HEX` overrides the store).
 
 Stdout is the machine interface: `{"ready":true}` after the first presented frame,
-`stats: …` once per second (Ctrl+Alt+Shift+S toggles, `--stats` forces on), one
+`stats: …` once per second while the overlay tier isn't Off (always the full detailed
+text, whatever the OSD shows; `--stats` forces the overlay on), one
 `{"error"|"ended": …}` JSON line on the way out. Logs go to stderr. Exit codes: `0`
 clean end, `2` connect failed, `3` trust rejected / pairing required, `4` presenter
 init failed.
@@ -31,7 +32,9 @@ releases), Ctrl+Alt+Shift+D disconnects, F11 toggles fullscreen; the controller
 chord (L1+R1+Start+Select, hold to disconnect) works the same.
 
 The default build carries the Skia console UI (`ui` feature): the stats OSD and capture
-hint render in-window (Ctrl+Alt+Shift+S toggles both the OSD and the stdout mirror).
+hint render in-window. Ctrl+Alt+Shift+S cycles the OSD tier live — Off → Compact (one
+line: fps · latency · Mb/s) → Normal (mode + end-to-end percentiles) → Detailed (decoder
+path + per-stage latency equation); any tier but Off also emits the stdout mirror.
 `--no-default-features` is the ~5 MB power-user build — same streaming, stats on stdout
 only, no Skia anywhere in the dependency tree.