Replace deploy workflow with portable Windows release build

- Remove old Docker-based deploy.yml
- Add release.yml: builds portable ZIP on tag push, uploads to Gitea
- Add build-dist.ps1: downloads embedded Python, installs deps, bundles app
- Add scrollbar-gutter: stable to prevent layout shift

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -0,0 +1,74 @@
+name: Build Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  build-windows:
+    runs-on: windows-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Build portable distribution
+        shell: pwsh
+        run: |
+          .\build-dist.ps1 -Version "${{ gitea.ref_name }}"
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: LedGrab-${{ gitea.ref_name }}-win-x64
+          path: build/LedGrab-*.zip
+          retention-days: 90
+
+      - name: Create Gitea release
+        shell: pwsh
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          $tag = "${{ gitea.ref_name }}"
+          $zipFile = Get-ChildItem "build\LedGrab-*.zip" | Select-Object -First 1
+          if (-not $zipFile) { throw "ZIP not found" }
+
+          $baseUrl = "${{ gitea.server_url }}/api/v1/repos/${{ gitea.repository }}"
+          $headers = @{
+            "Authorization" = "token $env:GITEA_TOKEN"
+            "Content-Type"  = "application/json"
+          }
+
+          # Create release
+          $body = @{
+            tag_name   = $tag
+            name       = "LedGrab $tag"
+            body       = "Portable Windows build — unzip, run ``LedGrab.bat``, open http://localhost:8080"
+            draft      = $false
+            prerelease = ($tag -match '(alpha|beta|rc)')
+          } | ConvertTo-Json
+
+          $release = Invoke-RestMethod -Method Post `
+            -Uri "$baseUrl/releases" `
+            -Headers $headers -Body $body
+
+          Write-Host "Created release: $($release.html_url)"
+
+          # Upload ZIP asset
+          $uploadHeaders = @{
+            "Authorization" = "token $env:GITEA_TOKEN"
+          }
+          $uploadUrl = "$baseUrl/releases/$($release.id)/assets?name=$($zipFile.Name)"
+          Invoke-RestMethod -Method Post -Uri $uploadUrl `
+            -Headers $uploadHeaders `
+            -ContentType "application/octet-stream" `
+            -InFile $zipFile.FullName
+
+          Write-Host "Uploaded: $($zipFile.Name)"