fix: Forge iframe fills full modal height (position:absolute)

.editor-body has flex height, so percentage height on iframe didn't work. Changed to position:absolute;inset:0 which fills the relative parent regardless of flex sizing.

frontend/app.js

@@ -3302,7 +3302,7 @@
       var iframe = document.createElement("iframe");
       iframe.id = "forge-iframe";
       iframe.src = "/editor-poc?vault=" + encodeURIComponent(data.vault) + "&path=" + encodeURIComponent(data.path);
-      iframe.style.cssText = "width:100%;height:100%;border:none;";
+      iframe.style.cssText = "position:absolute;top:0;left:0;width:100%;height:100%;border:none;";
       bodyEl.appendChild(iframe);
       modal.classList.add("active");
       safeCreateIcons();

frontend/js/viewer.js

@@ -507,7 +507,7 @@ export function renderFile(data) {
     var iframe = document.createElement("iframe");
     iframe.id = "forge-iframe";
     iframe.src = "/editor-poc?vault=" + encodeURIComponent(data.vault) + "&path=" + encodeURIComponent(data.path);
-    iframe.style.cssText = "width:100%;height:100%;border:none;";
+    iframe.style.cssText = "position:absolute;top:0;left:0;width:100%;height:100%;border:none;";
     bodyEl.appendChild(iframe);
     modal.classList.add("active");
     safeCreateIcons();