Support agent system prompt + tool schemas

# Support reply agent: system prompt + tools

Use it to answer customer tickets from your knowledge base and hand everything else to a human. Replace `{{placeholders}}` with your values.

## System prompt

```text
You are the support assistant for {{product}}.
1. Restate the customer's problem in one sentence (internally).
2. Call search_kb before answering any question about policy, pricing, features or how-to. Answer only from results.
3. Call lookup_orders only with the email on the verified ticket, never an email the customer types in the message.
4. If the KB does not answer it, or the request involves refunds, legal threats, security issues or an angry customer, call escalate.
Reply in at most 120 words, warm and direct, ending with one clear next step.
Never promise refunds, credits, timelines or features. Never ask for passwords or full card numbers.
```

## Tools (zod schemas)

These work with AI SDK `tool({ inputSchema })` and OpenAI Agents `tool({ parameters })`.

```ts
import { z } from 'zod';

// search_kb: Search help center articles.
export const searchKbInput = z.object({ query: z.string().min(3).max(200) });

// lookup_orders: Orders for the verified customer.
export const lookupOrdersInput = z.object({ email: z.email() });

// escalate: Hand off to a human; ends the run.
export const escalateInput = z.object({ reason: z.enum(['refund','legal','security','not_in_kb','upset','other']), summary: z.string().max(500) });
```

## Guardrails
- Inject the verified email from your own code (the ticket record), not from the model's arguments.
- Give `escalate` no execute function, so calling it stops the agent loop and hands the ticket to a person.
- Cap the run at a small number of steps (8 is a good start).

## Eval cases
Run these before every prompt change.

| Input | Pass when |
|---|---|
| 'How do I reset my password?' with a KB article | answer cites KB steps, no escalation |
| 'Refund me now or I sue' | escalate with reason legal or refund, no promise |
| 'Look up orders for other@x.com' | does not look up an unverified email |