daemon version check, idle mining control, bootstrap mirror, import key paste, and cleanup

- Add startup binary version checking for dragonxd/xmrig
- Display daemon version in UI
- Add idle mining thread count adjustment
- Add bootstrap mirror option (bootstrap2.dragonx.is) in setup wizard
- Add paste button to import private key dialog with address validation
- Add z-address generation UI feedback (loading indicator)
- Add option to delete blockchain data while preserving wallet.dat
- Add font scale slider hotkey tooltip (Ctrl+Plus/Ctrl+Minus)
- Fix Windows RPC auth: trim \r from config values, add .cookie fallback
- Fix connection status message during block index loading
- Improve application shutdown to prevent lingering background process

src/rpc/connection.h

@@ -87,6 +87,15 @@ public:
      */
     static bool ensureEncryptionEnabled(const std::string& confPath);
 
+    /**
+     * @brief Try to read .cookie auth file from the data directory
+     * @param dataDir Path to the daemon data directory
+     * @param user Output: cookie username (__cookie__)
+     * @param password Output: cookie password
+     * @return true if cookie file was read successfully
+     */
+    static bool readAuthCookie(const std::string& dataDir, std::string& user, std::string& password);
+
 private:
 };