refactor: drop milestone names + consolidate clients; loss-recovery & rumble fixes

Two bodies of work in one commit (the rename moved files the fixes also touched).

Naming/structure cleanup (pre-launch):
- Host modules m3.rs->punktfunk1.rs, m0.rs->spike.rs; CLI m3-host->punktfunk1-host,
  m0->spike; bare `punktfunk-host` now prints help. Types M3Options/M3Source->
  Punktfunk1Options/Punktfunk1Source.
- Clients consolidated out of crates/ into clients/: punktfunk-client-rs->
  clients/probe (crate punktfunk-probe), client-linux->clients/linux,
  client-windows->clients/windows, punktfunk-android->clients/android/native
  (crate punktfunk-client-android; kept [lib] name=punktfunk_android so the JNI
  contract is unchanged). crates/ now holds only core + host.
- Milestone codes M0-M4 purged from code/CLI/CLAUDE.md/README/docs/docs-site,
  kept only in docs/implementation-plan.md. docs/m2-plan.md->
  docs/gamestream-host-plan.md. CI/gradle/flatpak paths updated.

Client loss-recovery (video froze and never recovered after a brief drop):
- Export punktfunk_connection_frames_dropped through the C ABI (the core already
  tracked it for the client keyframe-recovery loop; it was never reachable from
  the ABI clients). Regenerated punktfunk_core.h.
- Apple (StreamPump + Stage2Pipeline) and Android (decode.rs) now poll
  frames_dropped and request a keyframe when it climbs -- the same loss-driven
  recovery Linux/Windows already had. Under infinite GOP the decoder silently
  conceals reference-missing frames, so the decode-error trigger rarely fires.

Apple rumble robustness (worked then went spotty -- DualSense + Xbox):
- Add CHHapticEngine stopped/reset handlers (rebuild on app background / audio
  interruption / server reset) and drop the permanent `broken` latch on a
  transient drive failure; latch only when the controller truly has no haptics.
- Surface swallowed SDL set_rumble errors on Linux/Windows + diagnostic logging.

Verified: cargo build/clippy/fmt --workspace, C-ABI harness, header drift.
Not runnable on this box (verify in CI): Gitea workflows, gradle/Android,
flatpak, Swift/decky.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/linux/Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name = "punktfunk-client-linux"
+description = "Native Linux punktfunk/1 client — GTK4/libadwaita shell, FFmpeg decode, PipeWire audio, SDL3 gamepads"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+authors.workspace = true
+repository.workspace = true
+
+[[bin]]
+name = "punktfunk-client"
+path = "src/main.rs"
+
+# Everything is Linux-gated so `cargo build --workspace` stays green on macOS (the Mac
+# client lives in clients/apple); on other platforms this builds as a stub binary.
+[target.'cfg(target_os = "linux")'.dependencies]
+punktfunk-core = { path = "../../crates/punktfunk-core", features = ["quic"] }
+
+# UI shell. GraphicsOffload needs GTK ≥ 4.14; black-background ≥ 4.16. AlertDialog/
+# PreferencesDialog need libadwaita ≥ 1.5.
+gtk = { package = "gtk4", version = "0.11", features = ["v4_16"] }
+adw = { package = "libadwaita", version = "0.9", features = ["v1_5"] }
+async-channel = "2"
+
+# Video decode (same FFmpeg pin as the host) and audio.
+ffmpeg-next = "8"
+opus = "0.3"
+pipewire = "0.9"
+
+# Gamepads: capture + feedback (full DualSense fidelity — touchpad/motion/triggers/LEDs
+# need the hidapi driver).
+sdl3 = { version = "0.18", features = ["hidapi"] }
+
+mdns-sd = "0.20"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+anyhow = "1"
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }