style: scope FontAwesome CDN to IDAA layout only

Move the FA 5.15.4 CDN <link> from app.html (global) into
src/routes/idaa/+layout.svelte <svelte:head> so it only loads
on /idaa/* routes. All other modules now use Lucide exclusively.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app.html

@@ -23,14 +23,6 @@
             rel="stylesheet"
         />
 
-        <link
-            rel="stylesheet"
-            href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.4/css/all.min.css"
-            integrity="sha512-1ycn6IcaQQ40/MKBW2W4Rhis/DbILU74C1vSrLJxCq57o941Ym01SwNsOMqvEBFlcgUa6xLiPY/NS5R+E6ztJQ=="
-            crossorigin="anonymous"
-            referrerpolicy="no-referrer"
-        />
-
         <!-- <link href="app.css" rel="stylesheet"> -->
 
         %sveltekit.head%

src/routes/idaa/+layout.svelte

@@ -255,6 +255,14 @@
 
 <svelte:head>
     <title>IDAA - {$idaa_loc?.title ?? 'Æ loading...'}</title>
+    <!-- FontAwesome 5 — used throughout IDAA module. Scoped here so it does not load on non-IDAA routes. -->
+    <link
+        rel="stylesheet"
+        href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.4/css/all.min.css"
+        integrity="sha512-1ycn6IcaQQ40/MKBW2W4Rhis/DbILU74C1vSrLJxCq57o941Ym01SwNsOMqvEBFlcgUa6xLiPY/NS5R+E6ztJQ=="
+        crossorigin="anonymous"
+        referrerpolicy="no-referrer"
+    />
     {#if $ae_loc.iframe}
         <!-- <meta name="robots" content="noindex, nofollow" /> -->
         <link