Prepare for Google Play Store and F-Droid release

📦 Release Preparation:
- Created comprehensive RELEASE_GUIDE.md
- Added signing key instructions
- Store listing content ready
- Screenshots checklist
- F-Droid preparation guide

🔐 Security:
- Updated .gitignore to exclude signing keys
- Protected key.properties from git
- Added *.jks and *.keystore exclusions

📝 Documentation Includes:
- Step-by-step signing key generation
- Google Play Store submission checklist
- F-Droid requirements and options
- Store assets specifications
- Privacy policy hosting options
- Version management guide

🏪 Store Listing Content:
- App title: "Sage - Kitchen Inventory Manager"
- Full description with features
- Category: Food & Drink
- Screenshots requirements (2-8 images)
- Feature graphic specs (1024x500)

⚠️ F-Droid Considerations:
- Firebase is proprietary (not FOSS)
- Options: Remove Firebase for F-Droid build
- Or: Provide APK downloads from GitHub
- Or: Self-host F-Droid repo

📱 Next Steps for Developer:
1. Generate signing key with keytool
2. Create key.properties file
3. Take screenshots (6 recommended)
4. Create feature graphic
5. Host privacy policy
6. Create Google Play Developer account ($25)
7. Build signed AAB: flutter build appbundle --release
8. Upload to Play Store

Version: 1.1.0+2
Package: com.github.mystiatech.sage

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.gitignore

@@ -43,3 +43,11 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# Release signing keys - NEVER COMMIT THESE!
+android/key.properties
+android/app/*.jks
+android/app/*.keystore
+
+# Store assets (optional - can commit if you want)
+store_assets/