feat(api): add OpenAPI 3.1 documentation

[Yusuke4869]

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[Copilot]

Pull Request Overview

This PR adds comprehensive OpenAPI 3.1 documentation to the API, replacing the basic Hono routing with OpenAPI-enabled routing and adding interactive documentation endpoints.

• Migrates from basic Hono routing to OpenAPI-enabled routing with schema definitions
• Adds interactive API documentation accessible via /doc and /doc/ui endpoints
• Implements authentication middleware for documentation access with token-based security

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/route/api.ts	Complete refactor to use OpenAPIHono with detailed route specifications and documentation endpoints
src/route/api.schema.ts	New comprehensive Zod schemas for API validation and OpenAPI documentation
src/middleware/doc.ts	New authentication middleware for securing documentation access
src/middleware/api.ts	Simplified API key validation logic by combining conditions
deno.json	Updated dependencies to include OpenAPI and Scalar documentation packages
.env.sample	Added API_DOC_TOKENS environment variable configuration

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