fix: player list styling and positioning tweaks

- Empty slots use subtle gray dashed line instead of solid characters
- Left/Right positions anchor to screen edges, never obscuring room code
- Player list enabled by default
- Fix VALID_TRANSITIONS.get() crash (plain object, not Map)

Made-with: Cursor

optimized-controls.html

@@ -317,14 +317,14 @@
         }
 
         #player-list-container.player-list-position-left {
-            right: 55%;
+            left: 24px;
             top: 50%;
             transform: translateY(-50%);
-            align-items: flex-end;
+            align-items: flex-start;
         }
 
         #player-list-container.player-list-position-right {
-            left: 55%;
+            right: 24px;
             top: 50%;
             transform: translateY(-50%);
             align-items: flex-start;
@@ -353,12 +353,17 @@
         }
 
         .player-slot-name.empty {
-            color: rgba(255,255,255,0.25);
-            font-style: italic;
+            color: transparent;
+            font-style: normal;
+            border-bottom: 2px dashed rgba(255,255,255,0.2);
+            min-width: 120px;
+            line-height: 0.8;
         }
 
         .player-slot-name.filled {
             color: #ffffff;
+            border-bottom: none;
+            min-width: 0;
         }
 
         /* Debug dashboard */
@@ -661,13 +666,13 @@
                 <div class="section-content">
                     <div class="control-row">
                         <label>Enable Player List:</label>
-                        <input type="checkbox" id="player-list-enabled">
+                        <input type="checkbox" id="player-list-enabled" checked>
                     </div>
                     <div class="control-row">
                         <label>Position:</label>
                         <select id="player-list-position">
-                            <option value="left">Left of Code</option>
-                            <option value="right">Right of Code</option>
+                            <option value="left">Left Side</option>
+                            <option value="right">Right Side</option>
                         </select>
                     </div>
                     <div class="control-row">