fix: clarify Kimi Platform login copy

[wbxl2000]

Related Issue

No linked issue.

Problem

The /login flow still referred to API key login as Moonshot AI Open Platform in several user-facing places, while the current flow should make the Kimi Platform API key path and save location clearer.

What changed

• Renamed the API key platform options to Kimi Platform labels with the corresponding console hosts.
• Added base URL and config save location details to the API key prompt.
• Updated the README and bilingual docs to match the new login wording.
• Added a changeset for the CLI and internal OAuth package.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

Verification

• git diff --check
• pnpm exec vitest run packages/oauth/test/open-platform.test.ts apps/kimi-code/test/tui/kimi-tui-startup.test.ts
• pnpm --filter @moonshot-ai/kimi-code-oauth typecheck
• pnpm --filter @moonshot-ai/kimi-code typecheck
• pnpm -C docs build

[changeset-bot]

🦋 Changeset detected

Latest commit: 2e0b253

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

This PR includes changesets to release 2 packages

Name	Type
@moonshot-ai/kimi-code-oauth	Patch
@moonshot-ai/kimi-code	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@2e0b253

npx https://pkg.pr.new/@moonshot-ai/kimi-code@2e0b253

commit: 2e0b253

[wbxl2000]

before:

after: