dashboard: show warning banner for [jaccl] RDMA driver errors

Detect errors containing "[jaccl]" in MetaInstance failure errors and
display a red dismissible alert banner. The tooltip explains this is a
macOS RDMA driver issue and that the affected machine needs to be
restarted. Alert re-appears if a new error arrives after dismissal.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

dashboard/src/routes/+page.svelte

@@ -181,6 +181,17 @@
   });
   let tb5InfoDismissed = $state(false);
 
+  // Detect [jaccl] RDMA driver errors from MetaInstance failure errors
+  const jacclError = $derived.by(() => {
+    for (const mi of Object.values(metaInstancesData)) {
+      if (mi.lastFailureError?.includes("[jaccl]")) {
+        return mi.lastFailureError;
+      }
+    }
+    return null;
+  });
+  let jacclDismissedError = $state<string | null>(null);
+
   // Helper to get friendly node name from node ID
   function getNodeName(nodeId: string): string {
     const node = data?.nodes?.[nodeId];
@@ -2018,8 +2029,71 @@
 </script>
 
 {#snippet clusterWarnings()}
-  {#if tbBridgeCycles.length > 0 || macosVersionMismatch || (tb5WithoutRdma && !tb5InfoDismissed)}
+  {#if tbBridgeCycles.length > 0 || macosVersionMismatch || (tb5WithoutRdma && !tb5InfoDismissed) || (jacclError && jacclError !== jacclDismissedError)}
     <div class="absolute top-4 left-4 flex flex-col gap-2 z-40">
+      {#if jacclError && jacclError !== jacclDismissedError}
+        <div class="group relative" role="alert">
+          <div
+            class="flex items-center gap-2 px-3 py-2 rounded border border-red-500/50 bg-red-500/10 backdrop-blur-sm cursor-help"
+          >
+            <svg
+              class="w-5 h-5 text-red-400 flex-shrink-0"
+              fill="none"
+              viewBox="0 0 24 24"
+              stroke="currentColor"
+              stroke-width="2"
+            >
+              <path
+                stroke-linecap="round"
+                stroke-linejoin="round"
+                d={warningIconPath}
+              />
+            </svg>
+            <span class="text-sm font-mono text-red-200">
+              JACCL RDMA ERROR
+            </span>
+            <button
+              type="button"
+              onclick={() => (jacclDismissedError = jacclError)}
+              class="ml-1 text-red-300/60 hover:text-red-200 transition-colors cursor-pointer"
+              title="Dismiss"
+            >
+              <svg
+                class="w-4 h-4"
+                fill="none"
+                viewBox="0 0 24 24"
+                stroke="currentColor"
+                stroke-width="2"
+              >
+                <path
+                  stroke-linecap="round"
+                  stroke-linejoin="round"
+                  d="M6 18L18 6M6 6l12 12"
+                />
+              </svg>
+            </button>
+          </div>
+
+          <!-- Tooltip on hover -->
+          <div
+            class="absolute top-full left-0 mt-2 w-80 p-3 rounded border border-red-500/30 bg-exo-dark-gray/95 backdrop-blur-sm opacity-0 invisible group-hover:opacity-100 group-hover:visible transition-all duration-200 z-50 shadow-lg"
+          >
+            <p class="text-xs text-white/80 mb-2">
+              A macOS RDMA driver error was detected. This is a known issue
+              with the experimental jaccl driver.
+            </p>
+            <p class="text-xs text-white/60 mb-2">
+              <span class="text-red-300">Error:</span>
+              {jacclError}
+            </p>
+            <p class="text-xs text-white/60">
+              <span class="text-red-300">To fix:</span> Restart the affected machine.
+              There is currently no other workaround for this issue.
+            </p>
+          </div>
+        </div>
+      {/if}
+
       {#if tbBridgeCycles.length > 0}
         {@const cycle = tbBridgeCycles[0]}
         {@const serviceName = getTbBridgeServiceName(cycle)}
@@ -2188,8 +2262,29 @@
 {/snippet}
 
 {#snippet clusterWarningsCompact()}
-  {#if tbBridgeCycles.length > 0 || macosVersionMismatch || (tb5WithoutRdma && !tb5InfoDismissed)}
+  {#if tbBridgeCycles.length > 0 || macosVersionMismatch || (tb5WithoutRdma && !tb5InfoDismissed) || (jacclError && jacclError !== jacclDismissedError)}
     <div class="absolute top-2 left-2 flex flex-col gap-1">
+      {#if jacclError && jacclError !== jacclDismissedError}
+        <div
+          class="flex items-center gap-1.5 px-2 py-1 rounded border border-red-500/50 bg-red-500/10 backdrop-blur-sm"
+          title="JACCL RDMA driver error — restart affected machine"
+        >
+          <svg
+            class="w-3.5 h-3.5 text-red-400"
+            fill="none"
+            viewBox="0 0 24 24"
+            stroke="currentColor"
+            stroke-width="2"
+          >
+            <path
+              stroke-linecap="round"
+              stroke-linejoin="round"
+              d={warningIconPath}
+            />
+          </svg>
+          <span class="text-[10px] font-mono text-red-200">JACCL ERROR</span>
+        </div>
+      {/if}
       {#if tbBridgeCycles.length > 0}
         <div
           class="flex items-center gap-1.5 px-2 py-1 rounded border border-yellow-500/50 bg-yellow-500/10 backdrop-blur-sm"