feat(desktop): surface effective-merged buzz-agent MCP servers in read-only panel

Wires the buzzAgentSlot prop that McpServersSection has exposed since
#1780 with the RuntimeConfigSurface.buzzAgentMcpServers field added in
P0. AgentConfigPanel now renders the effective merged (global <
definition < agent) enabled-server list via a new BuzzAgentMcpServerRow,
giving Will's WYSIWYG requirement (Q2) its read-only half. Also fixes
McpServersSection's fallback text, which previously rendered unreachable
for buzz-agent (the extensions-based branch never executes there since
buzz-agent always reports empty extensions).

Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>

desktop/src/features/agents/ui/AgentConfigPanel.tsx

@@ -17,7 +17,7 @@ import { useAgentConfigSurface } from "../hooks";
 import { cn } from "@/shared/lib/cn";
 import { copyTextToClipboard } from "@/shared/lib/clipboard";
 import { Spinner } from "@/shared/ui/spinner";
-import { McpServersSection } from "./McpServersSection";
+import { McpServersSection, BuzzAgentMcpServerRow } from "./McpServersSection";
 import type {
   ConfigField,
   ConfigOrigin,
@@ -366,8 +366,15 @@ export function AgentConfigPanel({
     );
   }
 
-  const { normalized, advanced, extensions, runtimeId, sources, isPreSpawn } =
-    data;
+  const {
+    normalized,
+    advanced,
+    extensions,
+    runtimeId,
+    sources,
+    isPreSpawn,
+    buzzAgentMcpServers,
+  } = data;
   const configFilePath = sources.configFilePath;
 
   const normalizedEntries = (
@@ -419,6 +426,19 @@ export function AgentConfigPanel({
       </div>
 
       <McpServersSection
+        buzzAgentSlot={
+          buzzAgentMcpServers.length > 0 ? (
+            <div className="divide-y divide-border/50">
+              {buzzAgentMcpServers.map((server) => (
+                <BuzzAgentMcpServerRow
+                  key={server.name}
+                  server={server}
+                  variant={advancedMode === "flat" ? "profile" : "compact"}
+                />
+              ))}
+            </div>
+          ) : undefined
+        }
         extensions={extensions}
         runtimeId={runtimeId}
         variant={advancedMode === "flat" ? "profile" : "compact"}

desktop/src/features/agents/ui/McpServersSection.tsx

@@ -1,6 +1,6 @@
 import type * as React from "react";
 import { CheckCircle2, CircleSlash } from "lucide-react";
-import type { ExtensionEntry } from "@/shared/api/types";
+import type { ExtensionEntry, McpServerConfig } from "@/shared/api/types";
 import { cn } from "@/shared/lib/cn";
 
 type McpServersSectionProps = {
@@ -38,9 +38,18 @@ export function McpServersSection({
         MCP Servers
       </p>
 
-      {isBuzzAgent && buzzAgentSlot ? buzzAgentSlot : null}
-
-      {extensions.length > 0 ? (
+      {isBuzzAgent ? (
+        (buzzAgentSlot ?? (
+          <p
+            className={cn(
+              "text-sm text-muted-foreground",
+              variant === "compact" ? "py-2" : "px-4 py-3",
+            )}
+          >
+            No custom servers configured
+          </p>
+        ))
+      ) : extensions.length > 0 ? (
         <div className="divide-y divide-border/50">
           {extensions.map((extension) => (
             <McpServerRow
@@ -100,3 +109,51 @@ function McpServerRow({
     </div>
   );
 }
+
+/**
+ * Read-only row for an *effective merged* buzz-agent MCP server — "what
+ * runs." Shows the resolved command line rather than `kind`/enabled state
+ * (unlike `McpServerRow`), since every entry here is already enabled by
+ * contract (`RuntimeConfigSurface.buzzAgentMcpServers` is enabled-only).
+ */
+export function BuzzAgentMcpServerRow({
+  server,
+  variant,
+}: {
+  server: McpServerConfig;
+  variant: "compact" | "profile";
+}) {
+  const StatusIcon = server.enabled ? CheckCircle2 : CircleSlash;
+  const commandLine = [server.command, ...server.args]
+    .filter(Boolean)
+    .join(" ");
+
+  return (
+    <div
+      className={cn(
+        "flex min-w-0 items-center gap-3",
+        variant === "compact" ? "py-2" : "px-4 py-3",
+      )}
+    >
+      <span className="flex h-8 w-8 shrink-0 items-center justify-center rounded-full bg-muted/50">
+        <StatusIcon
+          className={cn(
+            "h-4 w-4",
+            server.enabled ? "text-emerald-600" : "text-muted-foreground",
+          )}
+        />
+      </span>
+      <span className="min-w-0 flex-1">
+        <span className="block truncate text-sm font-medium text-foreground">
+          {server.name}
+        </span>
+        <span
+          className="mt-0.5 block truncate text-2xs text-muted-foreground/70"
+          title={commandLine || undefined}
+        >
+          {commandLine || "stdio"}
+        </span>
+      </span>
+    </div>
+  );
+}