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)

build-dist-windows.sh

@@ -390,8 +390,29 @@ rm -f "$ZIP_PATH"
 (cd "$BUILD_DIR" && zip -rq "$ZIP_NAME" "$DIST_NAME")
 
 ZIP_SIZE=$(du -h "$ZIP_PATH" | cut -f1)
+
+# ── Build NSIS installer (if makensis is available) ──────────
+
+SETUP_NAME="LedGrab-v${VERSION_CLEAN}-win-x64-setup.exe"
+SETUP_PATH="$BUILD_DIR/$SETUP_NAME"
+
+if command -v makensis &>/dev/null; then
+    echo "[9/8] Building NSIS installer..."
+    makensis -DVERSION="${VERSION_CLEAN}" "$SCRIPT_DIR/installer.nsi" >/dev/null 2>&1
+    if [ -f "$SETUP_PATH" ]; then
+        SETUP_SIZE=$(du -h "$SETUP_PATH" | cut -f1)
+        echo "  Installer: $SETUP_PATH ($SETUP_SIZE)"
+    else
+        echo "  WARNING: makensis ran but installer not found at $SETUP_PATH"
+    fi
+else
+    echo "[9/8] Skipping installer (makensis not found — install nsis to enable)"
+fi
+
 echo ""
 echo "=== Build complete ==="
-echo "  Archive: $ZIP_PATH"
-echo "  Size: $ZIP_SIZE"
+echo "  ZIP: $ZIP_PATH ($ZIP_SIZE)"
+if [ -f "$SETUP_PATH" ]; then
+    echo "  Installer: $SETUP_PATH ($SETUP_SIZE)"
+fi
 echo ""