fix(release-rust): don't fail Windows packaging when no DLLs exist

capslockx-windows builds without the `stt` feature (whisper-rs doesn't
compile on Windows), so sherpa-rs's build.rs is never invoked and no
runtime DLLs are produced. clx.exe runs as a STT-stub in that case;
the DLLs would only be needed if `stt` were enabled.

Bundle DLLs when present, skip silently when not, instead of throwing
"No DLLs found ... sherpa-rs build.rs may have failed".

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: snomiao

.github/workflows/release-rust.yml

@@ -76,13 +76,20 @@ jobs:
           # it to `clx.exe` so users get a clean PATH entry.
           Copy-Item rs\target\release\clx-rust.exe "$STAGE\clx.exe"
           Copy-Item rs\target\release\clx-screen-reader.exe "$STAGE\clx-screen-reader.exe"
-          # Runtime DLLs (sherpa-onnx-c-api.dll, onnxruntime.dll, etc.) are
-          # dropped by sherpa-rs's build.rs into target/release. Without these
-          # clx.exe fails with STATUS_DLL_NOT_FOUND (0xC0000135) at launch.
+          # Runtime DLLs (sherpa-onnx-c-api.dll, onnxruntime.dll, etc.)
+          # are dropped by sherpa-rs's build.rs into target/release WHEN
+          # the `stt` feature is enabled. capslockx-windows currently
+          # builds without stt (whisper-rs doesn't compile on Windows),
+          # so no DLLs are produced and clx.exe runs as a stt-stub
+          # (Space+V no-op). Bundle whatever DLLs exist; don't fail if
+          # there are none.
           $dlls = Get-ChildItem rs\target\release -Filter *.dll -ErrorAction SilentlyContinue
-          if (-not $dlls) { throw "No DLLs found in rs\target\release — sherpa-rs build.rs may have failed" }
-          foreach ($d in $dlls) { Copy-Item $d.FullName "$STAGE\" }
-          Write-Host "Bundled DLLs: $($dlls.Name -join ', ')"
+          if ($dlls) {
+            foreach ($d in $dlls) { Copy-Item $d.FullName "$STAGE\" }
+            Write-Host "Bundled DLLs: $($dlls.Name -join ', ')"
+          } else {
+            Write-Host "No runtime DLLs to bundle (stt feature off)"
+          }
           Copy-Item scripts\install.ps1 "$STAGE\install.ps1"
           @"
           `$InstallDir = "`$env:LOCALAPPDATA\CapsLockX"
@@ -103,7 +110,7 @@ jobs:
           # relative to script dir)
           Copy-Item rs\target\release\clx-rust.exe scripts\clx.exe
           Copy-Item rs\target\release\clx-screen-reader.exe scripts\clx-screen-reader.exe
-          Get-ChildItem rs\target\release -Filter *.dll | ForEach-Object {
+          Get-ChildItem rs\target\release -Filter *.dll -ErrorAction SilentlyContinue | ForEach-Object {
             Copy-Item $_.FullName "scripts\"
           }
           # Install NSIS + EnVar plugin