feat(simulation): add Worker AI polygon runtime and terrain navigation

simulation/ai-polygon/motion_control.py

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+"""Physics-clock command envelope; perception remains asynchronous.
+
+Limit wheel-surface acceleration without delaying a safety reduction. Scaling
+both sides together preserves the planner's requested curvature. Stops bypass
+the ramp, as required by the already qualified collision/braking envelope.
+This is a simulation actuator, not a VESC controller or a motor calibration.
+"""
+
+CONTROL_PROFILE = {
+    "clock": "physics-pre-step",
+    "rate_hz": 60,
+    "wheel_surface_acceleration_mps2": 0.2,
+    "safety_reductions": "immediate",
+    "authority": "simulation-only",
+}
+
+
+class DriveEnvelope:
+    def __init__(self, track_width=0.9, acceleration=0.2):
+        self.half_track = track_width / 2
+        self.acceleration = acceleration
+        self.wheels = (0.0, 0.0)
+
+    def step(self, velocity, yaw_rate, dt, *, stop=False):
+        requested = (velocity - yaw_rate * self.half_track, velocity + yaw_rate * self.half_track)
+        if stop or max(map(abs, requested)) < 1e-8:
+            self.wheels = (0.0, 0.0)
+            return 0.0, 0.0
+        scale = 1.0
+        for old, new in zip(self.wheels, requested, strict=True):
+            # Reversal starts from zero; never retain motion in the old direction.
+            prior = abs(old) if old * new >= 0 else 0.0
+            if abs(new) > prior:
+                scale = min(scale, (prior + self.acceleration * max(0.0, dt)) / abs(new))
+        self.wheels = tuple(value * scale for value in requested)
+        return velocity * scale, yaw_rate * scale