add Boris 13-tips (Jan 3) doc, rename tips files for consistency, and clean up README tips section

- Create tips/claude-boris-13-tips-03-jan-26.md from Boris's Jan 3 tweet thread (13 tips)
- Rename claude-boris-tips-feb-26.md → claude-boris-12-tips-12-feb-26.md for consistent naming
- Remove description hyperlinks for external-only URLs in Boris + Team section
- Add (Boris) attribution to Boris's tweets matching existing (Thariq) pattern
- Update all references in README.md and presentation/index.html

Co-Authored-By: Claude <noreply@anthropic.com>

presentation/index.html

@@ -1653,7 +1653,7 @@ managed-settings.json              <span class="comment"># Organization policy (
         <h1>Resources</h1>
         <div class="use-cases">
             <div class="use-case-item"><span class="use-case-icon">&#128214;</span><div class="use-case-text"><strong>Claude Code Docs</strong><span>code.claude.com/docs/en</span></div></div>
-            <div class="use-case-item"><span class="use-case-icon">&#128161;</span><div class="use-case-text"><strong>Boris Cherny's 12 Tips</strong><span>tips/claude-boris-tips-feb-26.md</span></div></div>
+            <div class="use-case-item"><span class="use-case-icon">&#128161;</span><div class="use-case-text"><strong>Boris Cherny's 12 Tips</strong><span>tips/claude-boris-12-tips-12-feb-26.md</span></div></div>
             <div class="use-case-item"><span class="use-case-icon">&#127959;</span><div class="use-case-text"><strong>This Repository</strong><span>Working examples of skills, agents, hooks, and the Command &rarr; Agent &rarr; Skills pattern</span></div></div>
             <div class="use-case-item"><span class="use-case-icon">&#128295;</span><div class="use-case-text"><strong>Claude Code Voice Hooks</strong><span>github.com/shanraisshan/claude-code-voice-hooks</span></div></div>
         </div>