Implement Bootstrap Paradox resolution for V3 site domain lookup

- Modified lookup_site_domain_v3 to strictly strip auth headers for guest lookup
- Enhanced /testing page with FQDN input and improved error visibility
- Updated TODO.md with Technical Debt refactoring roadmap
- Documented Unified Aether AI Agent (UE-AE-01) transition progress in GEMINI.md

src/routes/testing/+page.svelte

@@ -269,12 +269,54 @@
             last_result: final_result
         };
     }
+
+    import { lookup_site_domain_v3 } from '$lib/ae_core/ae_core__site';
+    let test_fqdn = $state('');
+
+    async function test_site_domain_search_v3() {
+        console.log('*** test_site_domain_search_v3() ***');
+        v3_test_result = 'loading...';
+
+        const fqdn = test_fqdn || window.location.host;
+        console.log('Testing FQDN:', fqdn);
+
+        try {
+            const result = await lookup_site_domain_v3({
+                api_cfg: $ae_api,
+                fqdn,
+                view: 'default',
+                log_lvl: 2
+            });
+
+            v3_test_result = {
+                fqdn,
+                result,
+                timestamp: new Date().toISOString()
+            };
+            console.log('Site Domain Search V3 Result:', result);
+        } catch (err: any) {
+            console.error('Error in test_site_domain_search_v3:', err);
+            v3_test_result = {
+                error: err.message || 'Unknown error',
+                stack: err.stack
+            };
+        }
+    }
 </script>
 
 <div class="container h-full mx-auto flex flex-col justify-center items-center p-4 gap-4">
     <div class="space-y-10 text-center flex flex-col items-center">
         <h1 class="h1">Aether - V3 API Testing</h1>
 
+        <div class="flex flex-col gap-2 w-full max-w-sm">
+            <input 
+                type="text" 
+                class="input" 
+                placeholder="FQDN (optional, defaults to current host)" 
+                bind:value={test_fqdn} 
+            />
+        </div>
+
         <div class="flex justify-center flex-wrap gap-2">
             <button class="btn variant-filled-primary" onclick={test_v3_get_id}>
                 Test V3 GET ID
@@ -303,10 +345,13 @@
             <button class="btn variant-filled-tertiary" onclick={test_person_v3_load}>
                 Test Person V3 Load
             </button>
+            <button class="btn variant-filled-warning" onclick={test_site_domain_search_v3}>
+                Test Site Domain Search V3
+            </button>
         </div>
     </div>
 
-    {#if v3_test_result}
+    {#if v3_test_result !== null}
         <div class="card p-4 w-full max-w-2xl bg-surface-100-800-token">
             <h3 class="h3">Test Result:</h3>
             <pre class="text-xs text-left overflow-auto max-h-96">