fix: portfolio polish - links, skills, nav, sitemap

- No-ill 프로젝트 링크 추가
- Skills에서 Redis Backend 중복 제거, Prometheus 추가
- Education 섹션 id 추가 및 nav 링크 추가
- Sitemap infra에 Tolchain RPC 추가
- Sitemap 홀수 카드 레이아웃 수정

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

index.html

@@ -22,6 +22,7 @@
       <a href="#skills" class="nav-link">Skills</a>
       <a href="#experience" class="nav-link">Experience</a>
       <a href="#projects" class="nav-link">Projects</a>
+      <a href="#education" class="nav-link">Education</a>
       <a href="#contact" class="nav-link">Contact</a>
       <a href="/sitemap/" class="nav-link nav-external">Sitemap</a>
     </div>
@@ -80,7 +81,6 @@
         <div class="skills-tags">
           <span class="tag">Go (Fiber)</span>
           <span class="tag">Spring</span>
-          <span class="tag">Redis</span>
           <span class="tag">WebSocket</span>
           <span class="tag">JWT</span>
         </div>
@@ -107,6 +107,7 @@
           <span class="tag">Caddy</span>
           <span class="tag">Linux</span>
           <span class="tag">CI/CD</span>
+          <span class="tag">Prometheus</span>
         </div>
       </div>
       <div class="skills-group">
@@ -171,7 +172,7 @@
       <div id="project-list" class="project-list"></div>
     </section>
 
-    <section class="section">
+    <section id="education" class="section">
       <h2 class="section-title">Education</h2>
       <div class="experience-list">
         <div class="experience-item">