hex position indicators: chair icons at hex edge midpoints replace gate-slot circles

- Split .gate-overlay into .gate-backdrop (z-100, blur) + .gate-overlay modal (z-120) so .table-position elements (z-110) render above backdrop but below modal
- New _table_positions.html partial: 6 .table-position divs with .fa-chair, role label, and .fa-ban/.fa-circle-check status icons; included unconditionally in room.html
- New epic:room view at /gameboard/room/<uuid>/; gatekeeper redirects there when table_status set; pick_roles redirects there
- role-select.js: adds .active glow to position on selectRole(); swaps .fa-ban→.fa-circle-check in placeCard onComplete; handleTurnChanged clears stale .active from all positions
- FTs: PositionIndicatorsTest (5 tests) + RoleSelectTest 8a/8b (glow + check state)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/templates/apps/gameboard/room.html

@@ -46,6 +46,7 @@
                         </div>
                     {% endfor %}
                 {% endif %}
+                {% include "apps/gameboard/_partials/_table_positions.html" %}
             </div>
         </div>