fix(studio): convert newlines to <br/> in AI message rendering

formatText now replaces \n with <br/> so AI responses display
with proper line breaks instead of a single unbroken block.

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

web/src/components/Studio.jsx

@@ -53,11 +53,9 @@ function renderContent(text) {
 }
 
 function formatText(text) {
-  // First escape HTML entities
   let html = text
     .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
   
-  // Apply markdown transformations (now with escaped brackets)
   html = html
     .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
     .replace(/`([^`]+)`/g, '<code class="inline-code">$1</code>')
@@ -66,10 +64,10 @@ function formatText(text) {
     .replace(/^# (.+)$/gm, '<h2 class="msg-h2">$1</h2>')
     .replace(/^\s*[-*] (.+)$/gm, '<div class="msg-bullet">• $1</div>')
     .replace(/^\s*(\d+)[.)] (.+)$/gm, '<div class="msg-step"><span class="msg-step-num">$1</span> $2</div>')
+    .replace(/\n/g, '<br/>')
   
-  // Sanitize: remove event handlers and dangerous protocols
   html = html
-    .replace(/\s+on\w+=["'][^"']*["']/gi, '') // Remove on* event handlers
+    .replace(/\s+on\w+=["'][^"']*["']/gi, '')
     .replace(/javascript:/gi, '')
     .replace(/data:/gi, '')