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/build.rs

@@ -17,4 +17,21 @@ fn main() {
         .unwrap_or_else(|| std::env::var("CARGO_PKG_VERSION").unwrap_or_else(|_| "unknown".into()));
     println!("cargo:rustc-env=PUNKTFUNK_VERSION={version}");
     println!("cargo:rerun-if-env-changed=PUNKTFUNK_BUILD_VERSION");
+
+    // Windows identity resources: the branded icon + version info. Task Manager / Explorer show a
+    // process by its version-info FileDescription — without one the host appears as a bare
+    // "punktfunk-host.exe" with no icon. Same winresource pattern as clients/windows and
+    // punktfunk-tray (cfg(windows) = build HOST, so Linux packaging builds skip it; CARGO_CFG_WINDOWS
+    // = TARGET).
+    #[cfg(windows)]
+    if std::env::var_os("CARGO_CFG_WINDOWS").is_some() {
+        let icon = "../../packaging/windows/branding/punktfunk.ico";
+        println!("cargo:rerun-if-changed={icon}");
+        winresource::WindowsResource::new()
+            .set_icon_with_id(icon, "1")
+            .set("FileDescription", "Punktfunk Host")
+            .set("ProductName", "Punktfunk")
+            .compile()
+            .expect("embed windows icon/version resources");
+    }
 }