Remove confusing pause/clear chart buttons from dashboard

The physics engine runs continuously, so pausing charts was misleading -
users might think the simulation stopped when it didn't. Charts now
always update automatically.

Also fix Streamlit deprecation warnings by replacing use_container_width
with width parameter (will be removed after 2025-12-31).

src/py_dvt_ate/simulation/server.py

@@ -57,17 +57,39 @@ class SimulationServer:
         self._instrument_server: InstrumentServer | None = None
         self._physics_task: asyncio.Task[None] | None = None
         self._running = False
+        self._paused = False  # Pause physics simulation
+        self._time_scale = 1.0  # Simulation time multiplier
 
     @property
     def is_running(self) -> bool:
         """Check if server is currently running."""
         return self._running
 
+    @property
+    def paused(self) -> bool:
+        """Check if physics simulation is paused."""
+        return self._paused
+
+    @paused.setter
+    def paused(self, value: bool) -> None:
+        """Pause or resume the physics simulation."""
+        self._paused = value
+
     @property
     def physics_engine(self) -> PhysicsEngine | None:
         """Get the physics engine instance."""
         return self._physics_engine
 
+    @property
+    def time_scale(self) -> float:
+        """Get the current time scale multiplier."""
+        return self._time_scale
+
+    @time_scale.setter
+    def time_scale(self, value: float) -> None:
+        """Set the time scale multiplier (e.g., 10.0 = 10x faster)."""
+        self._time_scale = max(0.1, min(value, 1000.0))
+
     def _setup(self) -> None:
         """Create and wire up all components."""
         # Create physics engine
@@ -101,8 +123,12 @@ class SimulationServer:
         dt = self._physics_engine.dt
 
         while self._running:
-            self._physics_engine.step()
-            # Sleep for the physics timestep
+            if not self._paused:
+                # Step physics multiple times based on time scale
+                steps_per_tick = max(1, int(self._time_scale))
+                for _ in range(steps_per_tick):
+                    self._physics_engine.step()
+            # Sleep for the physics timestep (wall clock time)
             await asyncio.sleep(dt)
 
     async def start(self) -> None: