Merge origin/main (shared clipboard Phase 1) into the local W6.2 + rumble-D line

Reconciles the two diverged mains: the local stack (W6.1/W6.2 crate decomposition,
lid-closed fixes, ABR climb gating, rumble root-fix A-D incl. the W7 core module
splits) x origin/main (clipboard wire ABI v8 + pf-clipboard + the macOS client).

Textual conflicts were trivial (host Cargo.toml dep union; Cargo.lock + the
cbindgen header regenerate). The real work was structural: the local line's W7
splits dissolved the two files the clipboard's Phase 0 landed in, so the merge
left both layouts side by side. Resolved by re-homing the clipboard delta into
the split layout and deleting the stale flat files:

- quic/msgs.rs -> quic/clip.rs (the 0x40-0x44 messages, CLIP_* vocabulary,
  codecs) + HOST_CAP_CLIPBOARD into quic/caps.rs beside GAMEPAD_STATE; mod.rs
  declares clip and fixes the split-by-concern doc.
- client.rs -> the client/ split: CtrlRequest clip variants + Negotiated.host_caps
  (control.rs), CLIP_EVENT_QUEUE (planes.rs), clip channel ends (worker.rs),
  NativeClient clip surface + channels (mod.rs), control-task encode/decode arms +
  the clipboard task spawn (pump.rs).

Verified on macOS: core 174/174 (merged rumble + clipboard suites), pf-clipboard
clippy -D warnings clean, fmt applied, header regenerated. Host-side compile
rides the Linux/Windows legs.

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

crates/punktfunk-host/Cargo.toml

@@ -41,6 +41,10 @@ pf-inject = { path = "../pf-inject" }
 # Virtual-display orchestration (per-compositor Linux backends + the Windows IddCx driver backend),
 # extracted to a subsystem crate (plan §W6). The DDC panel control + KWin zkde protocol moved with it.
 pf-vdisplay = { path = "../pf-vdisplay" }
+# Shared clipboard (design/clipboard-and-file-transfer.md §4): the per-OS session-clipboard
+# backends + coordinator. Portable dep — the crate's facade (policy / ClipCoordCmd / start)
+# compiles everywhere; the backends are cfg-gated inside it.
+pf-clipboard = { path = "../pf-clipboard" }
 # M3 native control plane (the `punktfunk/1` QUIC handshake; data plane stays native-thread UDP).
 quinn = "0.11"
 anyhow = "1"