Add comprehensive Electron build system and documentation

- Updated electron-builder.config.json with proper TimeSafari metadata
- Added Linux package support (AppImage, deb, rpm)
- Created build-packages.sh script for easy package building
- Added npm scripts for building from project root
- Created comprehensive README-BUILDING.md documentation
- Fixed package.json metadata (author, homepage, repository)
- Added maintainer information for Linux packages

Features:
- AppImage: Portable, no installation required (~145MB)
- Debian package: System integration via package manager (~96MB)
- RPM package: Support for RPM-based distributions
- Build scripts support individual or all package types

Usage:
- npm run electron:build (all packages)
- npm run electron:build:appimage (AppImage only)
- npm run electron:build:deb (Debian package only)
- cd electron && ./build-packages.sh [type]

package.json

@@ -25,6 +25,9 @@
     "electron:dev": "npm run build:capacitor && npx cap copy electron && cd electron && npm run electron:start",
     "electron:setup": "./scripts/setup-electron.sh",
     "electron:dev-full": "./scripts/electron-dev.sh",
+    "electron:build": "npm run build:capacitor && npx cap copy electron && cd electron && ./build-packages.sh",
+    "electron:build:appimage": "npm run build:capacitor && npx cap copy electron && cd electron && ./build-packages.sh appimage",
+    "electron:build:deb": "npm run build:capacitor && npx cap copy electron && cd electron && ./build-packages.sh deb",
     "clean:android": "adb uninstall app.timesafari.app || true",
     "build:android": "./scripts/build-android.sh",
     "fastlane:ios:beta": "cd ios && fastlane beta",