Group Back-to-project and Manage together, styled alike

Moves the back link from the far left to sit immediately left of the
Manage button (both now top right, in a new .project-head__actions
row), and switches it from .btn-secondary to .menu__toggle so the two
are visually identical rather than just similar.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/views/ProjectConfigureView.vue

@@ -150,13 +150,15 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKeydown))
 
     <template v-else-if="project">
       <div class="project-head">
-        <RouterLink :to="{ name: 'project', params: { id: projectId } }" class="btn-secondary project-head__back">
-          &larr; Back to project
-        </RouterLink>
-
         <h1 class="project-head__title">{{ project.title }}</h1>
 
-        <ProjectManageMenu :project-id="projectId" :project-title="project.title" :card-count="project.card_count" />
+        <div class="project-head__actions">
+          <RouterLink :to="{ name: 'project', params: { id: projectId } }" class="menu__toggle project-head__back">
+            &larr; Back to project
+          </RouterLink>
+
+          <ProjectManageMenu :project-id="projectId" :project-title="project.title" :card-count="project.card_count" />
+        </div>
       </div>
 
       <section class="config-section">