feat(zod-openapi): add defineOpenAPIRoute and openapiRoutes for batch route registration

[destroSunRay]

Note
This is my first time contributing to open-source, if I made mistakes I'm sorry. Any feedback is welcome.

Description

This PR adds two new utilities to improve route definition and registration in @hono/zod-openapi:

• defineOpenAPIRoute: Provides explicit type safety for route definitions
• openapiRoutes: Enables batch registration of multiple routes with full type safety

Problem

• Registering many routes individually was repetitive and verbose
• Type inference for complex route configurations was challenging
• Organizing routes across multiple files was difficult
• No built-in support for conditional route registration
• RPC type safety was hard to maintain across scattered route registrations

Solution

• defineOpenAPIRoute: Wraps route definitions with explicit types for better IDE support and type checking
• openapiRoutes: Accepts an array of route definitions and registers them all at once
• Supports addRoute flag for conditional registration
• Maintains full type safety and RPC support through recursive type merging
• Enables clean modular organization of routes

Benefits

• ✅ Reduced boilerplate code
• ✅ Better type inference and IDE autocomplete
• ✅ Easier code organization and maintainability
• ✅ Declarative conditional routes
• ✅ Full backward compatibility

Examples

See the updated README for usage examples.

Testing

• All existing tests pass (102/102)
• Added tests for new functionality
• Verified type inference works correctly

Documentation

• Updated package README with usage examples

[changeset-bot]

🦋 Changeset detected

Latest commit: 439cbcb

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@hono/zod-openapi	Minor

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[destroSunRay]

This pull request is the implementation for the proposed feature 1751.