phase5: add saved searches, watchlist, and authenticated htmx flows

templates/players/detail.html

@@ -12,7 +12,12 @@
         · {{ player.inferred_role.name|default:"No inferred role" }}
       </p>
     </div>
-    <a class="button ghost" href="{% url 'players:index' %}">Back to search</a>
+    <div class="row-gap">
+      {% if request.user.is_authenticated %}
+        {% include "scouting/partials/favorite_button.html" with player=player is_favorite=is_favorite next_url=request.get_full_path %}
+      {% endif %}
+      <a class="button ghost" href="{% url 'players:index' %}">Back to search</a>
+    </div>
   </div>
 
   <div class="detail-grid mt-16">