Add DMG installer creation for direct distribution

Adds `just dmg <version>` command to create a classic macOS DMG installer
with drag-to-Applications window. The DMG wraps the already-notarized app
so no separate notarization is needed.

Changes:
- scripts/create-dmg.sh: Creates DMG with custom background and icon layout
- assets/dmg-background.{svg,png}: Background image with arrow and instructions
- Justfile: Added `dmg` command
- RELEASE.md: Updated release steps to include DMG creation
- README.md: Moved Download section to top, added install instructions

Requires: brew install create-dmg

Author: bartTC

Justfile

@@ -93,6 +93,10 @@ log id:
 builds:
     @ls -d {{build_dir}}/v* {{build_dir}}/dev 2>/dev/null | xargs -I{} basename {} | sort -V || echo "(none)"
 
+# Create DMG installer (requires create-dmg: brew install create-dmg)
+dmg version="":
+    ./scripts/create-dmg.sh {{version}}
+
 # =============================================================================
 # App Store (requires Apple Distribution certificate)
 # =============================================================================

README.md

@@ -8,6 +8,12 @@ A Safari extension that displays CDN cache status (HIT/MISS) for the current pag
 ![Manifest V3](https://img.shields.io/badge/Manifest-V3-green)
 ![License MIT](https://img.shields.io/badge/License-MIT-yellow)
 
+## Download
+
+Download the latest release from [GitHub Releases](https://github.com/bartTC/CacheStatusSafariExtension/releases/latest).
+
+After downloading, unzip and move the app to your Applications folder. On first launch, open Safari → Settings → Extensions and enable Cache Status.
+
 ## Features
 
 - **Toolbar Badge** — Color-coded cache status (HIT/MISS) visible at a glance
@@ -100,6 +106,7 @@ just xcode        # Open project in Xcode
 ## Release Process
 
 See [RELEASE.md](RELEASE.md) for the full release guide covering:
+
 - Direct distribution (GitHub) with notarization
 - Mac App Store submission
 

RELEASE.md

@@ -64,6 +64,9 @@ just wait
 
 # 5. Staple notarization ticket and create final zip
 just staple
+
+# 6. Create DMG installer (optional, requires: brew install create-dmg)
+just dmg v0.0.6
 ```
 
 ### Output
@@ -73,7 +76,8 @@ build/
 └── v0.0.6/
     ├── CacheStatus.xcarchive       # Xcode archive
     ├── CF Cache Status.app         # Signed app
-    ├── CF.Cache.Status.v0.0.6.zip  # Final notarized release
+    ├── CF.Cache.Status.v0.0.6.zip  # Final notarized release (for GitHub)
+    ├── CacheStatus-v0.0.6.dmg      # DMG installer (optional)
     └── .submission_id              # Notarization tracking
 ```
 
@@ -206,6 +210,7 @@ Before releasing a new version:
 4. [ ] Push tag: `git push origin v0.0.X`
 5. [ ] Build releases:
    - [ ] `just release v0.0.X` (direct)
+   - [ ] `just dmg v0.0.X` (optional DMG installer)
    - [ ] `just release-appstore v0.0.X` (App Store)
-6. [ ] Create GitHub release with the `.zip` file
+6. [ ] Create GitHub release with `.zip` (and optionally `.dmg`)
 7. [ ] Submit App Store version in App Store Connect

assets/dmg-background.png

@@ -0,0 +1,73 @@
+#!/bin/bash
+set -e
+
+# Create DMG installer with drag-to-Applications window
+# Usage: ./scripts/create-dmg.sh [version]
+
+BUILD_DIR="${BUILD_DIR:-build}"
+
+if [[ -n "$1" ]]; then
+    ver="$1"
+elif [[ -f "$BUILD_DIR/.current_version" ]]; then
+    ver=$(cat "$BUILD_DIR/.current_version")
+else
+    echo "Error: No version specified"
+    exit 1
+fi
+
+ver_dir="$BUILD_DIR/$ver"
+app_path="$ver_dir/export/CF Cache Status.app"
+dmg_path="$ver_dir/CacheStatus-$ver.dmg"
+
+if [[ ! -d "$app_path" ]]; then
+    echo "Error: App not found at $app_path"
+    echo "Run 'just archive $ver' first."
+    exit 1
+fi
+
+# Remove existing DMG if present
+rm -f "$dmg_path"
+
+echo "Creating DMG for $ver..."
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+BACKGROUND="$SCRIPT_DIR/../assets/dmg-background.png"
+
+# Window layout (600x400):
+#
+#   ┌──────────────────────────────────────────────┐
+#   │                                              │
+#   │     [App Icon]    ───►    [Applications]     │
+#   │      x=150                   x=450           │
+#   │      y=85                    y=85            │
+#   │                                              │
+#   │        "Drag to Applications to install"     │
+#   │                                              │
+#   └──────────────────────────────────────────────┘
+
+create-dmg \
+    --volname "Cache Status" \
+    --volicon "$app_path/Contents/Resources/AppIcon.icns" \
+    --background "$BACKGROUND" \
+    --window-pos 200 120 \
+    --window-size 600 400 \
+    --icon-size 100 \
+    --icon "CF Cache Status.app" 150 125 \
+    --app-drop-link 450 125 \
+    --hide-extension "CF Cache Status.app" \
+    "$dmg_path" \
+    "$app_path"
+
+# Options explained:
+#   --volname         Name shown in Finder title bar and mounted volume
+#   --volicon         Icon for the mounted DMG volume
+#   --background      Background image (600x400 PNG with arrow/instructions)
+#   --window-pos      Where the Finder window opens on screen (x y from top-left)
+#   --window-size     Finder window dimensions (width height)
+#   --icon-size       Size of icons in the window (pixels)
+#   --icon            Position of the app: "Name.app" x y (from top-left of window)
+#   --app-drop-link   Position of Applications folder shortcut: x y
+#   --hide-extension  Hide .app extension for cleaner look
+
+echo ""
+echo "DMG created: $dmg_path"