fix(quota): use /v1/token_plan/remains and honor custom base URL

[kapelame]

What

mmx quota show (and region auto-detection) call a stale, hardcoded quota endpoint. Two problems in quotaEndpoint():

export function quotaEndpoint(baseUrl: string): string {
  // Quota endpoint uses api subdomain
  const host = baseUrl.includes('minimaxi.com') ? 'https://api.minimaxi.com' : 'https://api.minimax.io';
  return `${host}/v1/api/openplatform/coding_plan/remains`;
}

1. Ignores baseUrl — it rebuilds the host from a minimaxi.com substring check instead of using the argument. It's the only endpoint in endpoints.ts that doesn't use the passed baseUrl, so --base-url / MINIMAX_BASE_URL / custom gateways are silently dropped for quota.
2. Stale path — /v1/api/openplatform/coding_plan/remains. The server now serves quota at /v1/token_plan/remains (consistent with the Token Plan naming). This file originally used token_plan/remains; it was changed to the openplatform path and that path now misbehaves.

Evidence

With a line-matched API key (no OAuth needed):

path	result
…/v1/api/openplatform/coding_plan/remains	1004 cookie is missing, log in again
…/v1/token_plan/remains	✅ model_remains returned

Confirmed on both lines (api.minimax.io and api.minimaxi.com).

Changes

• src/client/endpoints.ts — return \${baseUrl}/v1/token_plan/remains`; drop the host rewrite. REGIONSbase URLs are alreadyapi.*` hosts, so no host fix-up is needed, and custom base URLs are now honored.
• src/config/detect-region.ts — region probe uses the same new path.
• Tests — update endpoints / sdk/quota / auth/timeout-fix expectations to the new path; add a test asserting a custom base URL is honored.

Verification

• bun test — 356 pass / 0 fail
• tsc --noEmit clean
• Live mmx quota show on both lines renders the quota table; --verbose confirms GET …/v1/token_plan/remains.

Scope

Independent of #173/#174 (those fix quota rendering); this fixes the quota endpoint. Branches off main.

[github-actions]

dummy

[github-actions]

Summary

Renames the quota endpoint from /v1/api/openplatform/coding_plan/remains → /v1/token_plan/remains and makes quotaEndpoint() honor custom base URLs instead of hardcoding api.minimaxi.com/api.minimax.io. This is a targeted, well-scoped fix. Test coverage for the new custom-base-URL behavior is included.

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Checks

Check	Result	Note
bun run typecheck	✅ Pass	No type errors
bun test	✅ Pass	356 tests across 56 files
bun run lint	⚠️ Pre-existing	14 problems (2 errors, 12 warnings) in unrelated files — not introduced by this PR

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Issues by File

No blocking issues in the changed files.

• src/client/endpoints.ts — clean
• src/config/detect-region.ts — clean
• test/auth/timeout-fix.test.ts, test/client/endpoints.test.ts, test/sdk/quota.test.ts — clean; all route strings updated consistently

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Suggestions (non-blocking)

The new test in test/client/endpoints.test.ts covers the custom base URL case nicely. One small thought: the route string /v1/token_plan/remains now appears in three files (endpoints.ts, detect-region.ts, and all the test mocks). If this path ever changes again, it would be easy to miss one. A shared constant could help, but it's not worth refactoring for — the current approach is clear enough.

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Verdict

✅ Approve — all required checks green, no blocking issues introduced by this PR.