[BUG] Error thrown for Object schemas

# Issue

I am getting an error recently regarding using.safeExtend(), somewhere inside @mcpjam/inspector,

which breaks in Zod v4.

# How to reproduce

1. Try to run: npx @mcpjam/inspector@latest
2. See error:

```

file:///Users/mattercoder/.npm/_npx/d1af9de5c448057a/node_modules/zod/v4/core/util.js:375
throw new Error("Object schemas containing refinements cannot be extended. Use `.safeExtend()` instead.");
^

Error: Object schemas containing refinements cannot be extended. Use `.safeExtend()` instead.
at Module.extend (file:///Users/mattercoder/.npm/_npx/d1af9de5c448057a/node_modules/zod/v4/core/util.js:375:15)
at inst.extend (file:///Users/mattercoder/.npm/_npx/d1af9de5c448057a/node_modules/zod/v4/classic/schemas.js:536:21)
at file:///Users/mattercoder/.npm/_npx/d1af9de5c448057a/node_modules/@mcpjam/inspector/dist/server/index.js:12026:45
at ModuleJob.run (node:internal/modules/esm/module_job:413:25)
at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:654:26)
at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)

Node.js v25.2.1
⚠️ Server did not become ready within 30s. Please visit http://127.0.0.1:6274 manually.

```

# Expected Behavior

MCPJam inspector should open in browser but it doesnt

# Screenshots

If applicable, add screenshots to help explain your problem.

# Platform

```
% node --version
v25.2.1
% npm --version
11.6.2
% uname -a
Darwin MacBook 25.4.0 Darwin Kernel Version 25.4.0: Thu Mar 19 19:31:09 PDT 2026; root:xnu-12377.101.15~1/RELEASE_ARM64_T8132 arm64

```

# Additional Context

Add any other context about the problem here.