fix: add xattr -cr instructions for unsigned app

- macOS Gatekeeper blocks unsigned apps as 'damaged'
- Added xattr -cr command in README install section
- Added note in landing page CTA section
- build-release.sh removes quarantine on local build
- Updated v0.3.0 release notes with install instructions

Author: leeyc09

README.md

@@ -229,9 +229,19 @@ Native SwiftUI app — load a video, configure settings, analyze, edit, and expo
 
 ```bash
 ./build-release.sh                # Build → dist/SilenciApp.app
-open dist/SilenciApp.app    # Launch
+open dist/SilenciApp.app          # Launch
 ```
 
+### Install from DMG
+
+1. Download `Silenci-vX.X.X-macOS.dmg` from [Releases](https://github.com/leeyc09/Silence-Cutter/releases)
+2. Open DMG → drag `SilenciApp` to Applications
+3. **Important (unsigned app):** Before first launch, run in Terminal:
+   ```bash
+   xattr -cr /Applications/SilenciApp.app
+   ```
+4. Open the app — Python environment auto-installs on first launch (~45s)
+
 ### First Launch — Auto Setup
 
 <div align="center">

build-release.sh

@@ -134,6 +134,15 @@ else
     echo "ℹ️  Install create-dmg for DMG packaging: brew install create-dmg"
 fi
 
+# 7. Remove quarantine attribute from app bundle
+echo ""
+echo "[7/7] Removing quarantine attribute…"
+xattr -cr "$APP_BUNDLE" 2>/dev/null
+echo "  ✅ Quarantine removed"
+
 echo ""
 echo "To run:"
 echo "  open $APP_BUNDLE"
+echo ""
+echo "⚠️  First launch on another Mac:"
+echo "  If macOS says 'damaged', run: xattr -cr /Applications/SilenciApp.app"

index.html

@@ -362,6 +362,7 @@ <h2 class="font-display font-extrabold text-4xl md:text-5xl lg:text-6xl text-whi
       </div>
 
       <p class="text-sm text-slate-500 mt-8">macOS 14+ &middot; Apple Silicon &middot; ~1.2 MB download &middot; Apache 2.0 License</p>
+      <p class="text-xs text-slate-600 mt-3">Unsigned app — after installing, run <code class="bg-white/[0.05] px-1.5 py-0.5 rounded text-slate-400">xattr -cr /Applications/SilenciApp.app</code> in Terminal before first launch</p>
     </div>
   </section>