docs(ai-gateway): show a real code-agent example (tool loop), not a raw fetch

Replace the bare fetch example with a compact ToolLoopAgent — a background
action triggered on a record, with tools that carry input schemas and a finish
tool — matching the SDK's house example style (no Deno/npm: scaffolding).
Keeps the "point any OpenAI-compatible client at baseURL/token" note.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: yardend-wix

src/modules/ai-gateway.types.ts

@@ -49,26 +49,41 @@ export interface AiGatewayModule {
    *
    * @example
    * ```typescript
-   * // Inside a backend function: hand the connection to any OpenAI-compatible client
-   * import { createClientFromRequest } from 'npm:@base44/sdk';
+   * import { ToolLoopAgent, tool, stepCountIs, hasToolCall } from "ai";
+   * import { createOpenAICompatible } from "@ai-sdk/openai-compatible";
+   * import { z } from "zod";
    *
-   * Deno.serve(async (req) => {
-   *   const base44 = createClientFromRequest(req);
-   *   const { baseURL, token } = base44.aiGateway.connection();
+   * const request = await base44.entities.ReturnRequest.get(returnId);
+   * const { baseURL, token } = base44.aiGateway.connection();
+   * // Point any OpenAI-compatible client at `baseURL` with `apiKey: token`.
+   * const models = createOpenAICompatible({ name: "base44", baseURL, apiKey: token });
    *
-   *   // Point any OpenAI-compatible client at `baseURL` with `apiKey: token`.
-   *   // Shown here with a raw request to the Chat Completions endpoint:
-   *   const res = await fetch(`${baseURL}/chat/completions`, {
-   *     method: 'POST',
-   *     headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${token}` },
-   *     body: JSON.stringify({
-   *       model: 'claude_sonnet_4_6',
-   *       messages: [{ role: 'user', content: 'Hello!' }],
+   * const agent = new ToolLoopAgent({
+   *   model: models("automatic"),
+   *   instructions:
+   *     "Decide whether this return looks fine or needs the owner's attention. " +
+   *     "Check the customer's past orders, then submit your verdict.",
+   *   tools: {
+   *     searchOrders: tool({
+   *       description: "This customer's past orders, optionally filtered by status",
+   *       inputSchema: z.object({ status: z.string().optional() }),
+   *       execute: ({ status }) => {
+   *         const query = { customer_email: request.customer_email };
+   *         if (status) query.status = status;
+   *         return base44.entities.Order.filter(query, "-created_date", 50);
+   *       },
    *     }),
-   *   });
-   *   const data = await res.json();
-   *   return Response.json({ text: data.choices[0].message.content });
+   *     submitVerdict: tool({
+   *       description: "Record the final verdict",
+   *       inputSchema: z.object({ decision: z.enum(["approved", "flagged"]), reason: z.string() }),
+   *       execute: ({ decision, reason }) =>
+   *         base44.entities.ReturnRequest.update(returnId, { status: decision, review_note: reason }),
+   *     }),
+   *   },
+   *   stopWhen: [stepCountIs(8), hasToolCall("submitVerdict")],
    * });
+   *
+   * await agent.generate({ prompt: `Review this return request: ${JSON.stringify(request)}` });
    * ```
    */
   connection(): AiGatewayConnection;