move extension tests out to their own directory

dev/CODING_STANDARDS.md

@@ -36,6 +36,7 @@ Tests for htmx are organized in the following manner:
   like set up a response mock using `mockResponse()`, create a live HTML button with the `createProcessedHTML` method, 
   invoke `click()` on the button, await the `"htmx:finally:request" event, and assert something about the updated DOM.
 * `/test/end2end` - These are end-to-end tests that do not fit in the other two categories
+* `/test/ext` - These tests are for the core extensions, which ship as part of htmx
 
 
 ## AI Policy

test/test.html

@@ -139,8 +139,6 @@
     <script src="./tests/attributes/hx-get.js"></script>
     <script src="./tests/attributes/hx-include.js"></script>
     <script src="./tests/attributes/hx-on.js"></script>
-    <script src="./tests/attributes/hx-optimistic.js"></script>
-    <script src="./tests/attributes/hx-preload.js"></script>
     <script src="./tests/attributes/hx-preserve.js"></script>
     <script src="./tests/attributes/hx-select.js"></script>
     <script src="./tests/attributes/hx-select-oob.js"></script>
@@ -149,6 +147,12 @@
     <script src="./tests/attributes/hx-trigger.js"></script>
     <script src="./tests/attributes/hx-vals.js"></script>
 
+    <!-- ============================================ -->
+    <!-- Extension Tests -->
+    <!-- ============================================ -->
+    <script src="./tests/ext/hx-optimistic.js"></script>
+    <script src="./tests/ext/hx-preload.js"></script>
+
     <!-- ============================================ -->
     <!-- End-to-End Tests -->
     <!-- ============================================ -->