ci(windows): split build into cargo + flutter; restore flutter/windows between

.gitea/workflows/build-windows.yml

@@ -212,11 +212,57 @@ jobs:
             fi
           fi
 
-      - name: Build RustDesk (build.py --portable --hwcodec --flutter --vram)
+      # The monolithic `python build.py` invocation that the upstream GitHub
+      # workflow uses runs cargo and `flutter build windows` back-to-back. On this
+      # self-hosted runner, *something* during the ~14min cargo build wipes out
+      # flutter/windows, which then makes the subsequent flutter build fail with
+      # "source directory does not exist" -- even though the diagnostic step
+      # immediately above confirms the dir is fully present at that moment.
+      # Splitting the build into discrete steps lets us restore flutter/windows
+      # right before flutter needs it, after cargo has finished.
+
+      - name: Cargo build (virtual_display dylib + main lib)
         shell: pwsh
         run: |
-          python .\build.py --portable --hwcodec --flutter --vram --skip-portable-pack
+          $features = "hwcodec,vram,flutter"
-          Move-Item -Force .\flutter\build\windows\x64\runner\Release .\rustdesk
+
+          Push-Location libs\virtual_display\dylib
+          cargo build --release
+          if ($LASTEXITCODE -ne 0) { throw "cargo build (virtual_display) failed" }
+          Pop-Location
+
+          cargo build --features $features --lib --release
+          if ($LASTEXITCODE -ne 0) { throw "cargo build (rustdesk lib) failed" }
+          if (-not (Test-Path target\release\librustdesk.dll)) {
+            throw "target\release\librustdesk.dll missing after cargo build"
+          }
+
+      - name: Restore flutter/windows if cargo build wiped it
+        shell: bash
+        run: |
+          if [ ! -d flutter/windows ]; then
+            echo "flutter/windows missing after cargo build -- restoring from git"
+            git status --porcelain | grep -E "flutter/windows" | head -10 || true
+            git checkout HEAD -- flutter/windows
+          fi
+          test -d flutter/windows && echo "flutter/windows present: $(find flutter/windows -type f | wc -l) files"
+          test -f flutter/windows/CMakeLists.txt || { echo "CMakeLists.txt missing"; exit 1; }
+
+      - name: Flutter build windows
+        shell: pwsh
+        run: |
+          Push-Location flutter
+          flutter build windows --release
+          if ($LASTEXITCODE -ne 0) { throw "flutter build windows failed" }
+          Pop-Location
+
+          # Mirror what build.py's build_flutter_windows() does after flutter build:
+          # copy the virtual_display dylib next to rustdesk.exe.
+          Copy-Item -Force `
+            target\release\deps\dylib_virtual_display.dll `
+            flutter\build\windows\x64\runner\Release\
+
+          Move-Item -Force flutter\build\windows\x64\runner\Release rustdesk
 
       - name: Bundle usbmmidd_v2 + printer driver
         shell: pwsh