fix: use PowerShell Get-FileHash for Windows checksum generation

- Replace certutil with PowerShell Get-FileHash command
- Get-FileHash is the standard Windows tool for hash generation
- Output format matches sha256sum format (hash + filename)
- Remove shell: bash to allow native shell execution on each platform

Author: Sisyphus Agent

.github/workflows/go.yml

@@ -176,10 +176,9 @@ jobs:
 
       - name: Create checksums
         working-directory: oho/dist
-        shell: bash
         run: |
           if [ "${{ matrix.goos }}" == "windows" ]; then
-            certutil -hashfile ${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }} SHA256 | grep -v "hash" | grep -v "CertUtil" | tr -d '\r' > ${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }}.sha256
+            powershell -Command "Get-FileHash -Algorithm SHA256 '${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }}' | ForEach-Object { `$_.Hash + '  ' + `$_.Path }" > ${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }}.sha256
           else
             sha256sum ${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }} > ${{ env.APP_NAME }}-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }}.sha256
           fi