1.3.18

Add multi-account support with account selection dialogs

• Add new AccountManager class to handle multiple Outlook accounts
  with isolated sessions and persistent storage
• Add tray menu integration for account management (rename, remove,
  auto-restore toggles)
• Add HTML-based account selection dialogs for mailto links and
  tray icon clicks with multiple accounts
• Add auto-restore functionality for accounts on startup
• Add email detection from page elements for account identification
• Update notification and badge systems to work with multiple accounts
• Add Open/Refresh/Hide options back to tray menu
• Clean up debug logging from recently added features

Full Changelog: 1.3.17.1.1...1.3.18