* feat: add anthropic-vertex provider for Claude via GCP Vertex AI Co-Authored-By: Claude Opus 4.6 <[email protected]> Signed-off-by: sallyom <[email protected]> * docs: add anthropic-vertex provider guide Co-Authored-By: Claude Opus 4.6 <[email protected]> Signed-off-by: sallyom <[email protected]> * Agents: validate Anthropic Vertex project env * Changelog: format update for Vertex entry * Providers: rename Anthropic Vertex to Google Vertex Claude * Providers: remove Vertex Claude provider path * Models: normalize Vercel Claude shorthand refs * Onboarding: default Vercel model to Claude shorthand * Changelog: add @vincentkoc credit for #23985 * Onboarding: keep canonical Vercel default model ref * Tests: expand Vercel model normalization coverage --------- Signed-off-by: sallyom <[email protected]> Co-authored-by: Claude Opus 4.6 <[email protected]> Co-authored-by: Vincent Koc <[email protected]>