feat: add NSIS Windows installer to release workflow

- installer.nsi: per-user install to AppData, Start Menu shortcuts,
  optional desktop shortcut and autostart, clean uninstall (preserves
  data/), Add/Remove Programs registration
- build-dist-windows.sh: runs makensis after ZIP if available
- release.yml: install nsis in CI, upload both ZIP and setup.exe
- Fix Docker registry login (sed -E for https:// stripping)

.gitea/workflows/release.yml

@@ -63,37 +63,50 @@ jobs:
       - name: Install system dependencies
         run: |
           sudo apt-get update
-          sudo apt-get install -y --no-install-recommends zip libportaudio2
+          sudo apt-get install -y --no-install-recommends zip libportaudio2 nsis
 
       - name: Cross-build Windows distribution
         run: |
           chmod +x build-dist-windows.sh
           ./build-dist-windows.sh "${{ gitea.ref_name }}"
 
-      - name: Upload build artifact
+      - name: Upload build artifacts
         uses: actions/upload-artifact@v3
         with:
           name: LedGrab-${{ gitea.ref_name }}-win-x64
-          path: build/LedGrab-*.zip
+          path: |
+            build/LedGrab-*.zip
+            build/LedGrab-*-setup.exe
           retention-days: 90
 
-      - name: Attach ZIP to release
+      - name: Attach assets to release
         env:
           GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
-          TAG="${{ gitea.ref_name }}"
           RELEASE_ID="${{ needs.create-release.outputs.release_id }}"
           BASE_URL="${{ gitea.server_url }}/api/v1/repos/${{ gitea.repository }}"
+
+          # Upload ZIP
           ZIP_FILE=$(ls build/LedGrab-*.zip | head -1)
-          ZIP_NAME=$(basename "$ZIP_FILE")
+          if [ -f "$ZIP_FILE" ]; then
+            curl -s -X POST \
+              "$BASE_URL/releases/$RELEASE_ID/assets?name=$(basename "$ZIP_FILE")" \
+              -H "Authorization: token $GITEA_TOKEN" \
+              -H "Content-Type: application/octet-stream" \
+              --data-binary "@$ZIP_FILE"
+            echo "Uploaded: $(basename "$ZIP_FILE")"
+          fi
 
-          curl -s -X POST \
-            "$BASE_URL/releases/$RELEASE_ID/assets?name=$ZIP_NAME" \
-            -H "Authorization: token $GITEA_TOKEN" \
-            -H "Content-Type: application/octet-stream" \
-            --data-binary "@$ZIP_FILE"
-
-          echo "Uploaded: $ZIP_NAME"
+          # Upload installer
+          SETUP_FILE=$(ls build/LedGrab-*-setup.exe 2>/dev/null | head -1)
+          if [ -f "$SETUP_FILE" ]; then
+            curl -s -X POST \
+              "$BASE_URL/releases/$RELEASE_ID/assets?name=$(basename "$SETUP_FILE")" \
+              -H "Authorization: token $GITEA_TOKEN" \
+              -H "Content-Type: application/octet-stream" \
+              --data-binary "@$SETUP_FILE"
+            echo "Uploaded: $(basename "$SETUP_FILE")"
+          fi
 
   # ── Linux tarball ──────────────────────────────────────────
   build-linux:
@@ -165,17 +178,19 @@ jobs:
         run: |
           TAG="${{ gitea.ref_name }}"
           VERSION="${TAG#v}"
-          REGISTRY="${{ gitea.server_url }}/${{ gitea.repository }}"
-          # Lowercase the registry path (Docker requires it)
-          REGISTRY=$(echo "$REGISTRY" | tr '[:upper:]' '[:lower:]' | sed 's|https\?://||')
+          # Strip protocol and lowercase for Docker registry path
+          SERVER_HOST=$(echo "${{ gitea.server_url }}" | sed -E 's|https?://||')
+          REPO=$(echo "${{ gitea.repository }}" | tr '[:upper:]' '[:lower:]')
+          REGISTRY="${SERVER_HOST}/${REPO}"
 
           echo "version=$VERSION" >> "$GITHUB_OUTPUT"
           echo "registry=$REGISTRY" >> "$GITHUB_OUTPUT"
+          echo "server_host=$SERVER_HOST" >> "$GITHUB_OUTPUT"
 
       - name: Login to Gitea Container Registry
         run: |
           echo "${{ secrets.GITEA_TOKEN }}" | docker login \
-            "$(echo '${{ gitea.server_url }}' | sed 's|https\?://||')" \
+            "${{ steps.meta.outputs.server_host }}" \
             -u "${{ gitea.actor }}" --password-stdin
 
       - name: Build Docker image