feat: enhance Windows compatibility for LibreOffice checks and subprocess handling

electron/app/utils/libreoffice-check.ts

@@ -275,6 +275,12 @@ export async function isLibreOfficeInstalled(): Promise<LibreOfficeCheckResult>
   // --- Step 1: check well-known paths synchronously (no exec overhead) ---
   for (const candidate of getCandidatePaths()) {
     if (fs.existsSync(candidate)) {
+      // On Windows, avoid probing with "--version" because some LibreOffice
+      // builds open a transient console window for this command.
+      if (process.platform === "win32") {
+        return { installed: true, path: candidate };
+      }
+
       // Binary found at a known location – try to get the version string.
       try {
         const quoted = `"${candidate}"`;
@@ -291,6 +297,26 @@ export async function isLibreOfficeInstalled(): Promise<LibreOfficeCheckResult>
   }
 
   // --- Step 2: try the PATH-based command ---
+  if (process.platform === "win32") {
+    try {
+      // Use "where" for PATH detection without launching LibreOffice itself.
+      const { stdout } = await execAsync("where soffice.exe", {
+        timeout: 8_000,
+        windowsHide: true,
+      });
+      const firstPath = stdout
+        .split(/\r?\n/)
+        .map((line) => line.trim())
+        .find((line) => line.length > 0);
+      if (firstPath) {
+        return { installed: true, path: firstPath };
+      }
+    } catch {
+      // Keep behavior: if PATH lookup fails, report not installed.
+    }
+    return { installed: false };
+  }
+
   try {
     const { stdout } = await execAsync("soffice --version", {
       timeout: 8_000,

electron/servers/fastapi/api/v1/ppt/endpoints/pptx_slides.py

@@ -26,7 +26,23 @@ def _get_soffice_binary() -> str:
     environment variable.  Falling back to the bare ``"soffice"`` command keeps
     Docker / server deployments working unchanged.
     """
-    return os.environ.get("SOFFICE_PATH") or "soffice"
+    configured = os.environ.get("SOFFICE_PATH")
+    if configured:
+        return configured
+    return "soffice.exe" if os.name == "nt" else "soffice"
+
+
+def _windows_hidden_subprocess_kwargs() -> Dict[str, object]:
+    """Return subprocess kwargs that suppress Windows console windows."""
+    if os.name != "nt":
+        return {}
+
+    startupinfo = subprocess.STARTUPINFO()
+    startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
+    return {
+        "creationflags": getattr(subprocess, "CREATE_NO_WINDOW", 0),
+        "startupinfo": startupinfo,
+    }
 
 
 PPTX_SLIDES_ROUTER = APIRouter(prefix="/pptx-slides", tags=["PPTX Slides"])
@@ -596,6 +612,7 @@ async def _convert_pptx_to_pdf(pptx_path: str, temp_dir: str) -> str:
                 text=True,
                 timeout=500,
                 env=env,
+                **_windows_hidden_subprocess_kwargs(),
             )
 
             print(f"LibreOffice PDF conversion output: {result.stdout}")