docs: add Atlas Cloud link and logo

[binyangzhu000-sudo]

Summary

• add a dedicated Atlas Cloud section to the LazyCodex README
• link the official Atlas Cloud logo and text to the campaign-tagged homepage
• use repository-local official SVG assets with light/dark theme support
• include a direct link to the Atlas Cloud coding plan

Validation

• passed the complete test suite: 9/9 tests
• passed npm run pack:dry-run
• parsed both SVG assets successfully with xmllint
• compared both repository-local SVG files byte-for-byte with the current official Atlas Cloud assets
• verified the homepage and coding-plan destinations return HTTP 200 with redirects followed
• rendered the full README through GitHub's GFM API and verified the linked <picture>, dark-theme source, fallback image, alt text, width, and destinations survive rendering
• ran git diff --check and a targeted credential-pattern scan

Scope

This is a documentation-only branding change. It updates the README and adds the two official theme-aware logo assets. No package metadata, runtime behavior, dependencies, or release configuration changes.

---

Summary by cubic

Adds an Atlas Cloud section to the README with a theme-aware logo and campaign‑tagged links to the homepage and coding plan. Previously the README had no Atlas Cloud branding; now it links out and includes two official SVGs with no runtime or package changes.

• Adds .github/assets/atlas-cloud-logo.svg and .github/assets/atlas-cloud-logo-white.svg; README uses a picture element for light/dark themes with alt text and width.
• Links: https://www.atlascloud.ai/?utm_source=github&utm_medium=link&utm_campaign=lazycodex and https://www.atlascloud.ai/console/coding-plan.
• Documentation-only; no migration required.

^{Written for commit 2401af1. Summary will update on new commits.}

[github-actions]

Thanks for the PR! Changes to LazyCodex land through oh-my-openagent — could you open this against omo-codex over there instead? PRs in this repository can't be merged.

If you're working with a coding agent, prompt it like this:

I opened #159 ("docs: add Atlas Cloud link and logo") against code-yeongyu/lazycodex, but changes there land through code-yeongyu/oh-my-openagent, where the Codex implementation lives under packages/omo-codex. Read my original PR, then open an equivalent PR against code-yeongyu/oh-my-openagent. In the new PR body, link the original PR (#159), explain that it was first opened against lazycodex, and describe in detail what that PR changed and why.

[binyangzhu000-sudo]

Canonical Atlas Cloud provider support now lives in code-yeongyu/oh-my-openagent#6826 under packages/omo-codex. This generated-distribution PR remains closed; future LazyCodex syncs will receive the provider runtime plus the managed README and official light/dark logo assets from the canonical source. No generated runtime is hand-edited here.