refactor: rename pf-vdisplay-proto -> pf-driver-proto (it spans all drivers)

The shared host<->driver ABI crate already contains more than the virtual
display: the IDD-push frame ring + control plane AND the gamepad shared-memory
layouts (XusbShm / PadShm). "pf-vdisplay-proto" was a misnomer — the name now
represents all the drivers it serves.

Mechanical rename, no behavior change:
- git mv crates/pf-vdisplay-proto -> crates/pf-driver-proto (package name +
  path-deps in the host crate and the driver workspace).
- pf_vdisplay_proto -> pf_driver_proto across host + driver Rust, both Cargo.lock
  files, the workspace members, the CI path triggers (windows-drivers.yml), and
  the docs/INF comments. The runtime Global\pfvd-* shared-object names are a
  SEPARATE contract and are deliberately untouched (host<->driver name matching).
- The pf-vdisplay DRIVER crate + its INF service name (Root\pf_vdisplay,
  UmdfService=pf_vdisplay, pf_vdisplay.dll) are unchanged — only the full
  `pf_vdisplay_proto` token was replaced, never the `pf_vdisplay` driver name.

Linux-verified: cargo test -p pf-driver-proto (const size-asserts compile) +
cargo clippy -p punktfunk-host -D warnings clean; Cargo.lock regenerated. The
driver-workspace side (path-dep + imports + its Cargo.lock) is Windows-CI-gated.

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

packaging/windows/drivers/Cargo.lock

@@ -398,7 +398,7 @@ checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 name = "pf-vdisplay"
 version = "0.0.1"
 dependencies = [
- "pf-vdisplay-proto",
+ "pf-driver-proto",
  "thiserror",
  "wdk",
  "wdk-build",
@@ -408,7 +408,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "pf-vdisplay-proto"
+name = "pf-driver-proto"
 version = "0.0.1"
 dependencies = [
  "bytemuck",
@@ -776,7 +776,7 @@ dependencies = [
 name = "wdk-probe"
 version = "0.0.1"
 dependencies = [
- "pf-vdisplay-proto",
+ "pf-driver-proto",
  "wdk",
  "wdk-build",
  "wdk-sys",