fix(plugins): reject malformed channel registrations

scripts/e2e/lib/kitchen-sink-plugin/assertions.mjs

@@ -241,6 +241,7 @@ function assertInstalled() {
 
     const expectedErrorMessages = new Set([
       "only bundled plugins can register agent tool result middleware",
+      'channel "kitchen-sink-channel-probe" registration missing required config helpers',
       "cli registration missing explicit commands metadata",
       "only bundled plugins can register Codex app-server extension factories",
       "http route registration missing or invalid auth: /kitchen-sink/http-route",

src/plugins/channel-validation.test.ts

@@ -114,4 +114,26 @@ describe("normalizeRegisteredChannelPlugin", () => {
       'channel "demo" meta.id mismatch ("other-demo"); using registered channel id',
     ]);
   });
+
+  it("rejects runtime channel registrations without required config helpers", () => {
+    const { diagnostics, pushDiagnostic } = collectDiagnostics();
+
+    const normalized = normalizeRegisteredChannelPlugin({
+      pluginId: "demo-plugin",
+      source: "/tmp/demo/index.ts",
+      plugin: createChannelPlugin({
+        id: "broken-channel",
+        config: undefined as never,
+      }),
+      pushDiagnostic,
+    });
+
+    expect(normalized).toBeNull();
+    expect(diagnostics).toEqual([
+      expect.objectContaining({
+        level: "error",
+        message: 'channel "broken-channel" registration missing required config helpers',
+      }),
+    ]);
+  });
 });

src/plugins/channel-validation.ts

@@ -50,6 +50,19 @@ export function normalizeRegisteredChannelPlugin(params: {
     });
     return null;
   }
+  if (
+    typeof params.plugin.config?.listAccountIds !== "function" ||
+    typeof params.plugin.config?.resolveAccount !== "function"
+  ) {
+    pushPluginValidationDiagnostic({
+      level: "error",
+      pluginId: params.pluginId,
+      source: params.source,
+      message: `channel "${id}" registration missing required config helpers`,
+      pushDiagnostic: params.pushDiagnostic,
+    });
+    return null;
+  }
 
   const rawMeta = params.plugin.meta as Partial<ChannelMeta> | undefined;
   const rawMetaId = normalizeOptionalString(rawMeta?.id);