Add mine-when-idle, default banlist, and console parsing improvements

Mine-when-idle:
- Auto-start/stop mining based on system idle time detection
- Platform::getSystemIdleSeconds() via XScreenSaver (Linux) / GetLastInputInfo (Win)
- Settings: mine_when_idle toggle + configurable delay (30s–10m)
- Settings page UI with checkbox and delay combo

Console tab:
- Shell-like argument parsing with quote and JSON bracket support
- Pass JSON objects/arrays directly as RPC params
- Fix selection indices when lines are evicted from buffer

Connection & status bar:
- Reduce RPC connect timeout to 1s for localhost fast-fail
- Fast retry timer on daemon startup and external daemon detection
- Show pool mining hashrate in status bar; sidebar badge reflects pool state

UI polish:
- Add logo to About card in settings; expose logo dimensions on App
- Header title offset-y support; adjust content-area margins
- Fix banned peers row cursor position (rawRowPosB.x)

Branding:
- Update copyright to "DragonX Developers" in RC and About section
- Replace logo/icon assets with updated versions

Misc:
- setup.sh: checkout dragonx branch before pulling
- Remove stale prebuilt-binaries/xmrig/.gitkeep

src/util/platform.h

@@ -123,6 +123,14 @@ public:
      * @return Combined daemon RSS in MB, or 0 if no daemon found
      */
     static double getDaemonMemoryUsageMB();
+
+    /**
+     * @brief Get system-wide idle time in seconds
+     * Uses platform-specific APIs: GetLastInputInfo (Windows),
+     * XScreenSaverQueryInfo via dlopen (Linux), IOKit (macOS).
+     * @return Seconds since last user input, or 0 on failure
+     */
+    static int getSystemIdleSeconds();
 };
 
 /**