Render API doc markdown as native Javadoc HTML in doc comments

Regenerated doc comments with genkit's new docfmt renderer, which
parses spec descriptions as CommonMark and emits Javadoc-native HTML
instead of leaking raw markdown:

- inline backticks -> {@code} (falls back to <code> when hazardous)
- fenced code examples -> <pre>{@code ...}</pre> (escaped <pre><code>
  for samples containing @ or unbalanced braces)
- markdown links -> <a href> anchors (reference-style links previously
  rendered as literal brackets with orphaned URL definitions)
- bullet/numbered lists -> <ul>/<ol> with <li> (previously broken by
  word-wrap, leaving list markers dangling mid-line)
- **bold**/_italic_ -> <b>/<i>; &, <, >, */ escaped for Javadoc

Generated from the exact OpenAPI spec sha the SDK is pinned to
(.codegen/_openapi_sha), so the diff is doc-comment-only: every changed
line is inside a /** */ block, verified mechanically. Output formatted
with google-java-format (same paragraph <p> placement as Spotless).

Co-authored-by: Isaac

Author: tanmay-db