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/resources/embedded_resources.h

@@ -55,6 +55,11 @@ const EmbeddedTheme* getEmbeddedThemes();
 // Returns number of themes extracted
 int extractBundledThemes(const std::string& destDir);
 
+// Update stale bundled theme files in the given directory.
+// Compares on-disk file size to embedded size; overwrites on mismatch.
+// Returns number of themes updated.
+int updateBundledThemes(const std::string& dir);
+
 // Check if daemon needs to be extracted
 bool needsDaemonExtraction();