fix: honor configured quota output format

[SaladDay]

Summary

• use the resolved config output for quota responses
• honor explicit flags, MINIMAX_OUTPUT, and saved config consistently
• add a TTY regression test while preserving credential routing and quota count handling

Supersedes #209. Thanks @shaoohh for identifying the issue and the original fix direction.

Validation

• npx bun test (415 passed)
• npx bun run typecheck
• npx bun run lint (one pre-existing warning)
• npx bun run build:dev
• git diff --check

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