feat(P.3.7): selection-to-command demo — RMB-to-move with 3 speed classes

- lib-core.command 0.1.0 dep added
- 6 stones gain speed (100/150/200 px/s pairs)
- RMB → move selected stones (target_provider = selection.list)
- command.update(dt) after selection.update(dt)

manifest.module

@@ -11,6 +11,7 @@
         {"id":"lib-core.selection","version":"0.1.0"},
         {"id":"lib-core.input","version":"0.3.0"},
         {"id":"lib-core.player_control","version":"0.1.0"},
-        {"id":"lib-core.interaction","version":"0.1.0"}
+        {"id":"lib-core.interaction","version":"0.1.0"},
+        {"id":"lib-core.command","version":"0.1.0"}
     ]
 }