fix: auto-height on file load so entire content is visible

Added autoHeight() helper called after ta.value is set in both demo mode and API load. Previously only triggered on input event, so loaded files only showed first line (scrollHeight was 0 until user typed).

frontend/editor-poc.html

@@ -491,6 +491,7 @@ body { font-family: var(--sans); background: var(--bg); color: var(--text); heig
     if (!fileVault || !filePath) {
       // Demo mode
       ta.value = '# Demo Document\n\nType **/** for commands. Select text for formatting.\n\n## Features\n\n- Slash commands: type / at start of line\n- Bubble menu: select text\n- AI actions: use the sparkle button or slash /ai\n- Preview: click the eye button\n';
+      autoHeight();
       statFile.textContent = 'Demo mode';
       document.title = 'ObsiGate Forge — Demo';
       originalContent = ta.value;
@@ -506,6 +507,7 @@ body { font-family: var(--sans); background: var(--bg); color: var(--text); heig
       })
       .then(function(data) {
         ta.value = data.raw || '';
+        autoHeight();
         originalContent = ta.value;
         // Extract title from first # heading or filename
         var title = filePath.split('/').pop().replace(/\.md$/, '');
@@ -1058,10 +1060,14 @@ body { font-family: var(--sans); background: var(--bg); color: var(--text); heig
 
   ta.addEventListener('input', function() {
     updateStats(); markDirty();
-    // Auto-height: grow textarea to fit content (no double scrollbar)
+    autoHeight();
+  });
+
+  // ---- Auto-height textarea ----
+  function autoHeight() {
     ta.style.height = 'auto';
     ta.style.height = ta.scrollHeight + 'px';
-  });
+  }
   ta.addEventListener('mouseup', function() { setTimeout(showBubble, 50); });
   // Bubble follows cursor on any selection change (keyboard too)
   document.addEventListener('selectionchange', function() {