feat: add Fedora/RHEL RPM package support with comprehensive documentation

Add native RPM package building for Fedora-based distributions:
- Extend electron-builder configuration to include RPM target
- Add rpm-build installation to GitHub Actions CI/CD workflow
- Update artifact upload patterns to include .rpm files
- Declare proper RPM dependencies (gtk3, libnotify, nss, etc.)
- Use xz compression for optimal package size

Documentation:
- Update README.md with Fedora/RHEL installation instructions
- Create comprehensive docs/install-fedora.md guide covering:
  - Installation methods (dnf/yum, direct URL)
  - System requirements and capabilities
  - Configuration and troubleshooting
  - SELinux handling and firewall rules
  - Performance tips and security considerations
  - Building from source
- Support for Fedora 39+, RHEL 9+, Rocky Linux, AlmaLinux

End-to-end support enables Fedora users to install Automaker via:
  sudo dnf install ./Automaker-<version>-x86_64.rpm

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

README.md

@@ -197,11 +197,30 @@ npm run build:electron
 # Platform-specific builds
 npm run build:electron:mac     # macOS (DMG + ZIP, x64 + arm64)
 npm run build:electron:win     # Windows (NSIS installer, x64)
-npm run build:electron:linux   # Linux (AppImage + DEB, x64)
+npm run build:electron:linux   # Linux (AppImage + DEB + RPM, x64)
 
 # Output directory: apps/ui/release/
 ```
 
+**Linux Distribution Packages:**
+
+- **AppImage**: Universal format, works on any Linux distribution
+- **DEB**: Ubuntu, Debian, Linux Mint, Pop!\_OS
+- **RPM**: Fedora, RHEL, Rocky Linux, AlmaLinux, openSUSE
+
+**Installing on Fedora/RHEL:**
+
+```bash
+# Download the RPM package
+wget https://github.com/AutoMaker-Org/automaker/releases/latest/download/Automaker-<version>-x86_64.rpm
+
+# Install with dnf (Fedora)
+sudo dnf install ./Automaker-<version>-x86_64.rpm
+
+# Or with yum (RHEL/CentOS)
+sudo yum localinstall ./Automaker-<version>-x86_64.rpm
+```
+
 #### Docker Deployment
 
 Docker provides the most secure way to run Automaker by isolating it from your host filesystem.