Add Windows Terminal installer (install.ps1 / install.bat)

install.ps1 copies bash.exe to %LOCALAPPDATA%\Programs\BashForWindows,
adds it to the user PATH, and injects a "Bash for Windows" profile into
Windows Terminal's settings.json so the shell appears in the + dropdown.

install.bat is a double-click wrapper that bypasses the PS execution policy.

build.sh --release produces a release/ folder ready to zip and distribute.
Supports -Uninstall flag to cleanly remove everything.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

build.sh

@@ -2,18 +2,39 @@
 set -e
 
 BUILD_DIR="build"
+RELEASE_DIR="release"
 mkdir -p "$BUILD_DIR"
 
 echo "=== Building bash-for-windows ==="
 
-# Linux build
-echo "  -> Linux..."
+# Linux debug build
+echo "  -> Linux (debug)..."
 go build -ldflags="-s -w" -o "$BUILD_DIR/bash-windows" .
 
-# Windows cross-compile
+# Windows release build
 echo "  -> Windows (x86_64)..."
-GOOS=windows GOARCH=amd64 CGO_ENABLED=0 go build -ldflags="-s -w" -o "$BUILD_DIR/bash-windows.exe" .
+GOOS=windows GOARCH=amd64 CGO_ENABLED=0 \
+    go build -ldflags="-s -w" -o "$BUILD_DIR/bash-windows.exe" .
 
 echo ""
 echo "=== Build complete ==="
 ls -lh "$BUILD_DIR/"
+
+# ── Release package ───────────────────────────────────────────────────────────
+if [[ "${1:-}" == "--release" ]]; then
+    echo ""
+    echo "=== Building release package ==="
+    rm -rf "$RELEASE_DIR"
+    mkdir -p "$RELEASE_DIR"
+
+    cp "$BUILD_DIR/bash-windows.exe" "$RELEASE_DIR/bash.exe"
+    cp install.ps1 "$RELEASE_DIR/"
+    cp install.bat "$RELEASE_DIR/"
+
+    echo ""
+    echo "Release folder: $RELEASE_DIR/"
+    ls -lh "$RELEASE_DIR/"
+    echo ""
+    echo "Distribute the contents of $RELEASE_DIR/ as a zip."
+    echo "Users run install.bat (or install.ps1) to install."
+fi