Fix BUG-001 and BUG-002; add post-submission QA test plan and QA entry

BUG-001: cache-on-save plugin clears page cache on onFormProcessed so
new entries appear in the tracker feed immediately after submission.

BUG-002: disabled Twig template cache (twig.cache: false) so theme
file changes take effect without a manual cache flush.

Also adds bugs-and-fixes.md, corrects TC-P test URLs (.entry suffix),
fixes TC-P.1 expectation (inline login form, not a redirect), and
creates the QA test entry for automated scenario verification.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/cache-on-save/cache-on-save.php

@@ -0,0 +1,26 @@
+<?php
+namespace Grav\Plugin;
+
+use Grav\Common\Plugin;
+use RocketTheme\Toolbox\Event\Event;
+
+class CacheOnSavePlugin extends Plugin
+{
+    public static function getSubscribedEvents(): array
+    {
+        return [
+            'onFormProcessed' => ['onFormProcessed', 0],
+        ];
+    }
+
+    public function onFormProcessed(Event $event): void
+    {
+        $form = $event['form'];
+        if (!$form) {
+            return;
+        }
+        if ($form->getName() === 'new-entry') {
+            $this->grav['cache']->clear();
+        }
+    }
+}

plugins/cache-on-save/cache-on-save.yaml

@@ -0,0 +1 @@
+enabled: true