Function envVarsMiddleware

envVarsMiddleware(
    schema: EnvVarSchema,
): (
    req: { method: string },
    res: { json: (body: unknown) => void },
    next: () => void,
) => void
Express middleware that auto-responds to HTTP OPTIONS requests with the application's environment variable schema, enabling jambonz portal discovery.
Parameters
- schema: EnvVarSchema
  The environment variable schema to expose.
Returns (
    req: { method: string },
    res: { json: (body: unknown) => void },
    next: () => void,
) => void
Example
```
import { envVarsMiddleware } from '@jambonz/sdk/webhook';

const envVars = {
  API_KEY: { type: 'string', description: 'Your API key', required: true },
};
app.use(envVarsMiddleware(envVars));
```
- Defined in src/webhook/env-vars.ts:24