Fix Zod type compatibility with @modelcontextprotocol/sdk

The SDK imports Zod from 'zod/v4' while this package imported from
'zod'. Although both resolve to the same version (3.25.x), TypeScript
sees them as separate modules with incompatible type declarations.

This caused type errors when:
- Extending SDK schemas like RequestSchema.extend()
- Passing SDK schemas to setRequestHandler/setNotificationHandler
- Using ZodObject/ZodLiteral types from different import paths

Changes:
- Import zod from 'zod/v4' to match SDK import path
- Update z.record() calls to use Zod v4 signature (requires both
  key and value schemas)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jonathanhefner

src/app-bridge.ts

@@ -1,5 +1,5 @@
 import { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import { ZodLiteral, ZodObject } from "zod";
+import { ZodLiteral, ZodObject } from "zod/v4";
 
 import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
 import {

src/types.ts

@@ -12,7 +12,7 @@ import {
   Tool,
   ToolSchema,
 } from "@modelcontextprotocol/sdk/types.js";
-import { z } from "zod";
+import { z } from "zod/v4";
 
 /**
  * Type-level assertion that validates a Zod schema produces the expected interface.
@@ -314,7 +314,7 @@ export interface McpUiToolInputNotification {
 export const McpUiToolInputNotificationSchema = z.object({
   method: z.literal("ui/notifications/tool-input"),
   params: z.object({
-    arguments: z.record(z.unknown()).optional(),
+    arguments: z.record(z.string(), z.unknown()).optional(),
   }),
 });
 
@@ -353,7 +353,7 @@ export interface McpUiToolInputPartialNotification {
 export const McpUiToolInputPartialNotificationSchema = z.object({
   method: z.literal("ui/notifications/tool-input-partial"),
   params: z.object({
-    arguments: z.record(z.unknown()).optional(),
+    arguments: z.record(z.string(), z.unknown()).optional(),
   }),
 });