feat(docs): add AI assistant interface and code copy button

Add new AI assistant chat interface with features:
- Real-time chat with markdown support
- Chat history management
- Citation tracking
- Selection-to-query functionality

Also adds code copy button to documentation code blocks and adjusts layout/styling.

Breaking changes: None

docs/md_v2/core/ask-ai.md

@@ -0,0 +1,74 @@
+<div class="ask-ai-container">
+<iframe id="ask-ai-frame" src="../../ask_ai/index.html" width="100%" style="border:none; display: block;" title="Crawl4AI Assistant"></iframe>
+</div>
+
+<script>
+// Iframe height adjustment
+function resizeAskAiIframe() {
+  const iframe = document.getElementById('ask-ai-frame');
+  if (iframe) {
+    const headerHeight = parseFloat(getComputedStyle(document.documentElement).getPropertyValue('--header-height') || '55');
+    // Footer is removed by JS below, so calculate height based on header + small buffer
+    const topOffset = headerHeight + 20; // Header + buffer/margin
+
+    const availableHeight = window.innerHeight - topOffset;
+    iframe.style.height = Math.max(600, availableHeight) + 'px'; // Min height 600px
+  }
+}
+
+// Run immediately and on resize/load
+resizeAskAiIframe(); // Initial call
+let resizeTimer;
+window.addEventListener('load', resizeAskAiIframe);
+window.addEventListener('resize', () => {
+    clearTimeout(resizeTimer);
+    resizeTimer = setTimeout(resizeAskAiIframe, 150);
+});
+
+// Remove Footer & HR from parent page (DOM Ready might be safer)
+document.addEventListener('DOMContentLoaded', () => {
+    setTimeout(() => { // Add slight delay just in case elements render slowly
+        const footer = window.parent.document.querySelector('footer'); // Target parent document
+        if (footer) {
+            const hrBeforeFooter = footer.previousElementSibling;
+            if (hrBeforeFooter && hrBeforeFooter.tagName === 'HR') {
+                hrBeforeFooter.remove();
+            }
+            footer.remove();
+            // Trigger resize again after removing footer
+            resizeAskAiIframe();
+        } else {
+             console.warn("Ask AI Page: Could not find footer in parent document to remove.");
+        }
+    }, 100); // Shorter delay
+});
+</script>
+
+<style>
+#terminal-mkdocs-main-content {
+    padding: 0 !important;
+    margin: 0;
+    width: 100%;
+    height: 100%;
+    overflow: hidden; /* Prevent body scrollbars, panels handle scroll */
+}
+
+/* Ensure iframe container takes full space */
+#terminal-mkdocs-main-content .ask-ai-container {
+    /* Remove negative margins if footer removal handles space */
+     margin: 0;
+    padding: 0;
+    max-width: none;
+    /* Let the JS set the height */
+    /* height: 600px; Initial fallback height */
+    overflow: hidden; /* Hide potential overflow before JS resize */
+}
+
+/* Hide title/paragraph if they were part of the markdown */
+/* Alternatively, just remove them from the .md file directly */
+/* #terminal-mkdocs-main-content > h1,
+#terminal-mkdocs-main-content > p:first-of-type {
+    display: none;
+} */
+
+</style>