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/assets/copy_code.js

@@ -0,0 +1,62 @@
+// ==== File: docs/assets/copy_code.js ====
+
+document.addEventListener('DOMContentLoaded', () => {
+    // Target specifically code blocks within the main content area
+    const codeBlocks = document.querySelectorAll('#terminal-mkdocs-main-content pre > code');
+
+    codeBlocks.forEach((codeElement) => {
+        const preElement = codeElement.parentElement; // The <pre> tag
+
+        // Ensure the <pre> tag can contain a positioned button
+        if (window.getComputedStyle(preElement).position === 'static') {
+            preElement.style.position = 'relative';
+        }
+
+        // Create the button
+        const copyButton = document.createElement('button');
+        copyButton.className = 'copy-code-button';
+        copyButton.type = 'button';
+        copyButton.setAttribute('aria-label', 'Copy code to clipboard');
+        copyButton.title = 'Copy code to clipboard';
+        copyButton.innerHTML = 'Copy'; // Or use an icon like an SVG or FontAwesome class
+
+        // Append the button to the <pre> element
+        preElement.appendChild(copyButton);
+
+        // Add click event listener
+        copyButton.addEventListener('click', () => {
+            copyCodeToClipboard(codeElement, copyButton);
+        });
+    });
+
+    async function copyCodeToClipboard(codeElement, button) {
+        // Use innerText to get the rendered text content, preserving line breaks
+        const textToCopy = codeElement.innerText;
+
+        try {
+            await navigator.clipboard.writeText(textToCopy);
+
+            // Visual feedback
+            button.innerHTML = 'Copied!';
+            button.classList.add('copied');
+            button.disabled = true; // Temporarily disable
+
+            // Revert button state after a short delay
+            setTimeout(() => {
+                button.innerHTML = 'Copy';
+                button.classList.remove('copied');
+                button.disabled = false;
+            }, 2000); // Show "Copied!" for 2 seconds
+
+        } catch (err) {
+            console.error('Failed to copy code: ', err);
+            // Optional: Provide error feedback on the button
+            button.innerHTML = 'Error';
+            setTimeout(() => {
+                button.innerHTML = 'Copy';
+            }, 2000);
+        }
+    }
+
+    console.log("Copy Code Button script loaded.");
+});