Add skipValidation option for type-safe APIs without runtime validation

[Copilot]

Validation overhead can impact performance in production, and unexpected API response changes can break deployed applications. This PR adds a skipValidation option to use schemas purely for TypeScript type inference without runtime validation.

Changes

• Configuration: Added skipValidation to TypeFetcherConfig (global) and EndpointSchema (per-endpoint)
• Validation logic: Modified TypeFetcher.request() to skip validation when configured, with endpoint-level overriding global setting
• Type safety preserved: Schema-based type inference remains intact regardless of validation setting

Usage

// Global configuration
const client = new TypeFetcher({
  baseURL: "https://api.example.com",
  skipValidation: true  // Types inferred, validation skipped
});

// Per-endpoint override
const api = client
  .addEndpoint("GET", "/users", {
    response: z.array(UserSchema),
    skipValidation: true  // Skip for this endpoint
  })
  .addEndpoint("POST", "/users", {
    body: CreateUserSchema,
    response: UserSchema
    // Validates if global default is false
  });

The feature enables environment-based configuration (skip in production, validate in dev) and graceful handling of evolving API schemas without breaking type safety.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add "Suggestions Only" Option</issue_title>
<issue_description>Is your feature request related to a problem? Please describe.
Currently, validation can often impact performance. Additionally, if the data type of an API response changes unexpectedly, it could cause errors in applications that are already in production.

Describe the solution you'd like
We'd like to introduce an option to use the schema solely for response type inference, without performing actual validation. This feature would help us avoid validation errors in responses.

Describe alternatives you've considered
Since this is a core system feature, we haven't considered any alternatives.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add "Suggestions Only" Option #2

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