Add property conflict detection to JS ORM model hydration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/RSpade/Core/Js/Rsx_Js_Model.js

@@ -29,6 +29,27 @@ class Rsx_Js_Model {
         // This constructor filters out the __MODEL marker that was used to identify which class
         // to instantiate, keeping only the actual data properties on the instance.
         const { __MODEL, ...modelData } = data;
+
+        // Check for property conflicts before assignment
+        const modelName = __MODEL || this.constructor.name;
+        for (const key in modelData) {
+            if (key in this) {
+                if (typeof this[key] === 'function') {
+                    throw new Error(
+                        `Model property conflict: "${key}" from server response would overwrite ` +
+                        `a method on ${modelName}. Check the PHP model's fetch() or toArray() method ` +
+                        `to see if "${key}" should be excluded or renamed. If the JS method ${key}() ` +
+                        `is computing a value the server now provides, remove the JS method.`
+                    );
+                } else {
+                    throw new Error(
+                        `Model property conflict: "${key}" already exists on ${modelName} ` +
+                        `and would be overwritten by server response data.`
+                    );
+                }
+            }
+        }
+
         Object.assign(this, modelData);
     }