design: Sign out is a POST form in the mockups, tinted like the links

Owner's instruction (2026-10-09): in the kit Sign out had no hover tint and
stood out among Account and Help. The cause was in the design, not in the
implementation: the mockups drew Sign out as a link, the panel signs out
with a POST, and Bulma tints only a.navbar-item.

  - build.py: Sign out is a form with a submit button carrying navbar-item,
    as the real shell has to write it; all pages rebuilt.
  - theme.css: the form stretches the button across the menu and the button
    is handed Bulma's own hover / focus / active variables, so it answers
    like the entries above it. No width, no colour of its own.

check.py: 32 screens, 48 sp- classes, 0 violation(s); outlines.json unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/assets/panel-redesign/panel/build.py

@@ -81,7 +81,9 @@ def navbar(section, page):
             '            <a class="navbar-item" href="account.html"><i class="ti ti-key"></i>Account</a>',
             '            <a class="navbar-item" href="help.html"><i class="ti ti-help"></i>Help</a>',
             '            <hr class="navbar-divider">',
-            '            <a class="navbar-item" href="login.html"><i class="ti ti-logout"></i>Sign out</a>',
+            # Signing out changes state, so it is a POST: a form with a button, not a link.
+            '            <form method="post" action="login.html"><button type="submit" class="navbar-item">'
+            '<i class="ti ti-logout"></i>Sign out</button></form>',
             '          </div>', '        </div>', '      </div>', '    </div>', '  </div>', '</nav>',
             '<div class="sp-perf" aria-hidden="true"></div>']
     return "\n".join(out)