`@cloudflare/tanstack-ai` adapter fails with "Connection error" on Gemma 4 / Qwen models when tools array is empty

When using `chat()` from `@tanstack/ai` with `createWorkersAiChat` from `@cloudflare/tanstack-ai` and providing no tools, the underlying stream crashes and falls back to non-streaming, which also crashes.

**Root Cause:**
`@tanstack/ai` defaults to passing `tools: []` into the adapter when no tools are configured. The `@cloudflare/tanstack-ai` adapter maps this directly to `env.AI.run(model, { tools: [] })`.

Models like `@cf/google/gemma-4-26b-a4b-it` and `@cf/qwen/qwen3-30b-a3b-fp8` run on vLLM, which strictly rejects `tools: []` with an `HTTP 400` error:

`Value error, 'tools' must not be an empty array. Either provide at least one tool or omit the field entirely.`

This causes `env.AI.run` to throw a connection error in streaming mode, and the fallback non-streaming request immediately throws the same error.

**Proposed Fix:**
In `@cloudflare/tanstack-ai`, the `createWorkersAiBindingFetch` (or adapter parsing logic) should delete the `tools` property if it receives an empty array before calling `binding.run()`.

```typescript
if (inputs && Array.isArray(inputs.tools) && inputs.tools.length === 0) {
delete inputs.tools;
}
```

Start at createWorkersAiBindingFetch in @cloudflare/tanstack-ai and trace how chat() inputs reach binding.run(). Verify the adapter's empty-tools path for Gemma 4 and Qwen models, then confirm that calls with no tools omit the tools property and no longer produce the reported connection error.

Written by the indexing model from the issue text.