feat: comprehensive model management enhancements and platform fixes

- Block 1: Refactored path logic into a centralized PathResolver for OS-agnostic and relative path handling.
- Block 2: Improved platform compatibility (shutdown, macOS menu, System Tray fallback).
- Block 3: Added Power-User features (Model Updater, Smart Cleanup, Thumbnails, Node Sync, Remote Status).
- Fixes: Recursive subfolder scanning, archive detection logic, and UI progress throttling.

src/main/java/de/tki/comfymodels/domain/ModelInfo.java

@@ -7,6 +7,7 @@ public class ModelInfo {
     private String name;
     private String url;
     private String size = "Unknown";
+    private long byteSize = -1;
     private String popularity = ""; // Download-Zahlen zur Sicherheit
     private String base;
     private String save_path;
@@ -30,6 +31,8 @@ public class ModelInfo {
     public void setUrl(String url) { this.url = url; }
     public String getSize() { return size; }
     public void setSize(String size) { this.size = size; }
+    public long getByteSize() { return byteSize; }
+    public void setByteSize(long byteSize) { this.byteSize = byteSize; }
     public String getPopularity() { return popularity; }
     public void setPopularity(String popularity) { this.popularity = popularity; }