design: two final polish nits from the confirmation review

- Auth signup domain parenthetical #888→#969696 (4.27→5.12:1, full AA).
- Sidebar org-name label gets a 44px touch height on mobile.

Design confirmation review: Visual 5 / UX 5 / Layout 5 / Accessibility 5,
overall 5.0, all objective a11y checks pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R7Q9ZKSZRTdvrSJkYLUmYs

internal/webapp/authlocal.go

@@ -598,7 +598,7 @@ func (a *BuiltinAuth) pageLogin(w http.ResponseWriter, r *http.Request) {
 	if a.AllowSignup {
 		note := ""
 		if len(a.AllowedDomains) > 0 {
-			note = ` <span style="color:#888">(` + html.EscapeString(a.domainList()) + ` only)</span>`
+			note = ` <span style="color:#969696">(` + html.EscapeString(a.domainList()) + ` only)</span>`
 		}
 		signup = fmt.Sprintf(`<p class="alt">No account? <a href="/auth/signup?next=%s">Sign up</a>%s</p>`, url.QueryEscape(next), note)
 	}

internal/webapp/static/style.css

@@ -346,6 +346,7 @@ body {
   /* The list rows are the primary tap targets — size them to 44px too. */
   #tree li > .row, #projects .row { min-height: 44px; }
   #invite-btn { min-height: 44px; padding: 0 16px; }
+  #org-name { min-height: 44px; display: inline-flex; align-items: center; }
   .nav-add { min-width: 44px; min-height: 44px; }
   .dir-history { min-width: 44px; min-height: 44px; display: inline-flex; align-items: center; justify-content: center; }
   .markdown, .admin, .onboard, .history { max-width: 100%; }