docs: add frontend UI architecture and ComfyUI widget guidelines

- Document dual UI systems: standalone web UI and ComfyUI custom node widgets
- Add ComfyUI widget development guidelines including styling and constraints
- Update terminology in LoraRandomizerNode from 'frontend/backend' to 'fixed/always' for clarity
- Include UI constraints for ComfyUI widgets: minimize vertical space, avoid dynamic height changes, keep UI simple

web/comfyui/loras_widget.js

@@ -699,6 +699,7 @@ export function addLorasWidget(node, name, opts, callback) {
       return widgetValue;
     },
     setValue: function(v) {
+      console.log('loras widget value update: ', v);
       // Remove duplicates by keeping the last occurrence of each lora name
       const uniqueValue = (v || []).reduce((acc, lora) => {
         // Remove any existing lora with the same name