feat(web): add X/Twitter icon to header nav

Link to @ericwang42 with X logo icon.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: lroolle

internal/web/templates.go

@@ -1805,6 +1805,7 @@ func renderTopNav(projectName, sessionID string) string {
 	b.WriteString(`</div>`)
 	b.WriteString(`</div>`)
 	b.WriteString(`<div class="nav-right">`)
+	b.WriteString(`<a href="https://x.com/ericwang42" target="_blank" rel="noopener noreferrer" class="icon-btn" title="@ericwang42"><svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor"><path d="M18.244 2.25h3.308l-7.227 8.26 8.502 11.24H16.17l-5.214-6.817L4.99 21.75H1.68l7.73-8.835L1.254 2.25H8.08l4.713 6.231zm-1.161 17.52h1.833L7.084 4.126H5.117z"/></svg></a>`)
 	b.WriteString(`<a href="https://github.com/thevibeworks/ccx" target="_blank" rel="noopener noreferrer" class="icon-btn" title="GitHub"><svg width="14" height="14" viewBox="0 0 16 16" fill="currentColor"><path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0016 8c0-4.42-3.58-8-8-8z"/></svg></a>`)
 	b.WriteString(`<button class="icon-btn" id="theme-toggle" title="Toggle theme (d)">◐</button>`)
 	b.WriteString(`<a href="/settings" class="icon-btn" title="Settings">◎</a>`)