fix: restore channel sdk schema typing

src/channels/plugins/config-schema.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it, vi } from "vitest";
 import { z } from "zod";
-import { buildChannelConfigSchema } from "./config-schema.js";
+import { buildChannelConfigSchema, emptyChannelConfigSchema } from "./config-schema.js";
 
 describe("buildChannelConfigSchema", () => {
   it("builds json schema when toJSONSchema is available", () => {
@@ -46,3 +46,22 @@ describe("buildChannelConfigSchema", () => {
     });
   });
 });
+
+describe("emptyChannelConfigSchema", () => {
+  it("accepts undefined and empty objects only", () => {
+    const result = emptyChannelConfigSchema();
+
+    expect(result.runtime?.safeParse(undefined)).toEqual({
+      success: true,
+      data: undefined,
+    });
+    expect(result.runtime?.safeParse({})).toEqual({
+      success: true,
+      data: {},
+    });
+    expect(result.runtime?.safeParse({ enabled: true })).toEqual({
+      success: false,
+      issues: [{ path: [], message: "config must be empty" }],
+    });
+  });
+});

src/channels/plugins/config-schema.ts

@@ -104,3 +104,33 @@ export function buildChannelConfigSchema(
     },
   };
 }
+
+export function emptyChannelConfigSchema(): ChannelConfigSchema {
+  return {
+    schema: {
+      type: "object",
+      additionalProperties: false,
+      properties: {},
+    },
+    runtime: {
+      safeParse(value) {
+        if (value === undefined) {
+          return { success: true, data: undefined };
+        }
+        if (!value || typeof value !== "object" || Array.isArray(value)) {
+          return {
+            success: false,
+            issues: [{ path: [], message: "expected config object" }],
+          };
+        }
+        if (Object.keys(value as Record<string, unknown>).length > 0) {
+          return {
+            success: false,
+            issues: [{ path: [], message: "config must be empty" }],
+          };
+        }
+        return { success: true, data: value };
+      },
+    },
+  };
+}