Keep the header buttons right-aligned once the title wraps below

.project-head__actions stretches full width on mobile along with the
title (align-items: stretch), but its own content was left-aligned by
default. Add justify-content: flex-end there under the same
breakpoint, and wrap ProjectView's ProjectManageMenu in a
.project-head__actions div (it wasn't before) so both views share one
selector for this instead of ProjectView needing its own.

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

web/src/style.css

@@ -216,6 +216,13 @@ body {
     flex-direction: column-reverse;
     align-items: stretch;
   }
+
+  /* .project-head's align-items: stretch above makes this full width too;
+     keep its actual content (Back/Manage) over on the right rather than
+     letting it default to the left edge. */
+  .project-head__actions {
+    justify-content: flex-end;
+  }
 }
 
 .sidebar__nav {