fix(classes.collection): Fix closure bug in Collection decorator by defining collection getter on original constructor and prototype

ts/classes.collection.ts

@@ -64,6 +64,20 @@ export function Collection(dbArg: SmartdataDb | TDelayed<SmartdataDb>) {
       configurable: true
     });
 
+    // Closure fix: When class methods reference the class name (e.g., `User.collection`),
+    // they get the original constructor via closure, not the decorated class.
+    // Define collection getter on the original constructor.
+    Object.defineProperty(constructor, 'collection', {
+      get: getCollection,
+      enumerable: false,
+      configurable: true
+    });
+    Object.defineProperty(constructor.prototype, 'collection', {
+      get: getCollection,
+      enumerable: false,
+      configurable: true
+    });
+
     // Deno compatibility note: Property decorators set properties on the prototype.
     // Since we removed instance property declarations from SmartDataDbDoc,
     // the decorator-set prototype properties are now accessible without shadowing.