refactor(card): redesign profile details with octicon labels

- Title becomes "login (Name)" (or just "login") instead of
  "Name's Profile Details".
- Row labels replaced with Octicon glyphs (repos, company, location,
  link, clock, people) rendered in the theme's muted color.
- Joined and account-age rows merge into a single "YYYY-MM-DD (N years
  ago)" line; years round down to whole years with month/day fallbacks.
- Drop profile-summary-for-github from README credits — no code from
  that project is used. github-profile-summary-cards is the only direct
  reference.

README.md

@@ -130,8 +130,7 @@ access token with `read:user` and `repo`, save it as a repo secret (e.g.
 
 ## Credits & inspiration
 
-- [**github-profile-summary-cards**](https://github.com/vn7n24fzkq/github-profile-summary-cards) by [@vn7n24fzkq](https://github.com/vn7n24fzkq) — card layout, chart styles, theme palette, and output structure.
-- [**profile-summary-for-github**](https://github.com/tipsy/profile-summary-for-github) by [@tipsy](https://github.com/tipsy) — the original profile-summary generator.
+- [**github-profile-summary-cards**](https://github.com/vn7n24fzkq/github-profile-summary-cards) by [@vn7n24fzkq](https://github.com/vn7n24fzkq) — card layout, chart styles, theme palette, Octicon selection, and output structure.
 
 ## License