feat: rename optimize to build with JSON output

[yusukebe]

Two changes for 0.2 (part of #77):

• Rename optimize to build. Plain hono build just bundles the app. --optimize applies the Hono-specific optimizations (the old behavior)
• Add the shared JSON output envelope in src/utils/output.ts: { ok, data } on success, { ok, error: { code, message, hint } } with exit code 1 on failure. build uses it as the first command. --plain gives the old human-readable text

request will move to the same envelope in the next PR.

The author should do the following, if applicable

• Add tests
• Run tests
• pnpm run format:fix && pnpm run lint:fix to format the code
• Add TSDoc/JSDoc to document the code