fix(app): embed Common-Controls v6 manifest so TaskDialogIndirect resolves

Symptom: jarvis-app.exe failed to start with a MessageBox saying
"Точка входа в процедуру TaskDialogIndirect не найдена в библиотеке
DLL ... jarvis-app.exe". Loader phase, no log lines ever written.

Cause: tray-icon 0.21 / winit 0.30 transitive Win32 imports include
TaskDialogIndirect from comctl32.dll, which is a Common-Controls v6
API. Without a side-by-side manifest declaring a dependency on
Microsoft.Windows.Common-Controls v6.0.0.0, Windows loads the legacy
v5 comctl32 (which does not export TaskDialogIndirect) and the
loader rejects the exe before main().

jarvis-gui does not hit this because tauri-build embeds its own
manifest as part of the Tauri compile step. jarvis-app had no
manifest at all.

Fix:
- app.manifest: Common-Controls v6 dependency, supportedOS for
  Win7..Win11, PerMonitorV2 DPI awareness, UTF-8 active code page,
  asInvoker execution level.
- app.manifest.rc: 3-line .rc that embeds the manifest with
  CREATEPROCESS_MANIFEST_RESOURCE_ID (1) and RT_MANIFEST (24).
- build.rs: on cfg(windows), embed_resource::compile() compiles the
  .rc and links the resulting .res into the exe. rerun-if-changed
  on the manifest sources.
- Cargo.toml: target-windows build-dependency on embed-resource 3.

Verified: jarvis-app.exe now runs cleanly through all init steps:
commands parsed, audio init, recorder init found "Микрофон (5-
Fifine Microphone)", IPC server up on ws://127.0.0.1:9712, VAD
already flushing frames.

UTF-8 active code page in the manifest also helps russian-character
fidelity when win32 APIs are invoked from PowerShell helpers.

Cargo.lock

@@ -3271,6 +3271,7 @@ name = "jarvis-app"
 version = "0.1.0"
 dependencies = [
  "dotenvy",
+ "embed-resource",
  "glib 0.21.5",
  "gtk",
  "image",