feat(host/windows): "Punktfunk Host" identity in Task Manager (icon + version info)

punktfunk-host.exe embedded no icon or version resources, so Task Manager and
Explorer showed a bare lowercase exe name with a generic icon. build.rs now
embeds the branded .ico + FileDescription "Punktfunk Host" / ProductName
"Punktfunk" via winresource (same pattern as the Windows client and the tray;
Linux packaging builds skip the block). The tray gets a matching "Punktfunk
Tray" description, and the SCM display name moves off lowercase
"punktfunk streaming host" to "Punktfunk Host" (applied idempotently by
`service install` on upgrade).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/punktfunk-host/Cargo.toml

@@ -243,3 +243,8 @@ nvenc = ["dep:nvidia-video-codec-sdk"]
 # so the LGPL build suffices and keeps the bundled DLLs LGPL, not GPL) at build time and bundles the
 # FFmpeg DLLs at runtime. Build the all-vendor GPU host with `--features nvenc,amf-qsv`.
 amf-qsv = ["dep:ffmpeg-next"]
+
+# Build-time icon/version-info embedding (build.rs; Windows dev/CI hosts only — Linux packaging
+# builds of this crate never execute the winresource block).
+[target.'cfg(windows)'.build-dependencies]
+winresource = "0.1"