fix: align runtime trust schema and built-in controls

web/workspace/src/routes/w/[workspaceId]/settings/runtimes/[runtimeId]/+page.svelte

@@ -219,7 +219,7 @@
       {/if}
     </section>
 
-    {#if data.workspace.permissions.manage_runtimes}
+    {#if data.workspace.permissions.manage_runtimes && !runtime.management.built_in}
       <section class="runtime-detail-section" aria-labelledby="runtime-trust-heading">
         <h2 id="runtime-trust-heading">Workspace trust</h2>
 

web/workspace/tests/runtime-management-source.test.ts

@@ -84,6 +84,10 @@ Deno.test("Runtime detail keeps trust controls owner-only and conflict-safe", as
   const reveal = page.indexOf("Reveal public key");
   const mutation = page.indexOf('id="runtime-public-key-input"');
   assert(ownerGate >= 0, "Runtime trust controls should use manage_runtimes");
+  assert(
+    page.includes("!runtime.management.built_in"),
+    "Runtime trust controls should be hidden for the built-in Runtime",
+  );
   assert(
     ownerGate < reveal && ownerGate < mutation,
     "owner gate should wrap key controls",