feat(web): implement Ship Dashboard with vitals and mobility sections

Adds NumericStepper and EnumDropdown UI components, VitalsSection (hull/armor/AC/con),
MobilitySection (speed/maneuver class/size), with debounced real-time updates.

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

web/src/components/ui/NumericStepper.tsx

@@ -0,0 +1,45 @@
+interface Props {
+  label: string;
+  value: number;
+  onChange: (value: number) => void;
+  min?: number;
+  max?: number;
+  step?: number;
+}
+
+export default function NumericStepper({ label, value, onChange, min = 0, max, step = 1 }: Props) {
+  const decrement = () => {
+    const next = value - step;
+    onChange(min !== undefined ? Math.max(min, next) : next);
+  };
+
+  const increment = () => {
+    const next = value + step;
+    onChange(max !== undefined ? Math.min(max, next) : next);
+  };
+
+  return (
+    <div className="stepper">
+      <span className="stepper-label">{label}</span>
+      <div className="stepper-controls">
+        <button
+          type="button"
+          className="stepper-btn"
+          onClick={decrement}
+          disabled={min !== undefined && value <= min}
+        >
+          -
+        </button>
+        <span className="stepper-value">{value}</span>
+        <button
+          type="button"
+          className="stepper-btn"
+          onClick={increment}
+          disabled={max !== undefined && value >= max}
+        >
+          +
+        </button>
+      </div>
+    </div>
+  );
+}