feat: 运动相机支持 + move_camera.txt 关键帧驱动

input.txt 新增：
  move_camera: 0  # 0=固定视角, 1=按 move_camera.txt 运动

move_camera.txt 格式（4列：帧号 距离 俯仰角 方位角）：
  0    40.0   0     0
  100  80.0  -30  180
  200  40.0   0   360

display.txt header 传递 camera_keyframes JSON 数组，
draw.py 按帧时间线性插值驱动相机运动（循环播放）。

dynamics.py

@@ -32,6 +32,31 @@ def _fmt_alpha(v):
     return str(float(v))
 
 
+def _load_camera_kf(config, runtime_base):
+    """加载 move_camera.txt → JSON 字符串，供 display.txt header 使用。"""
+    if not int(config.get("move_camera", 0)):
+        return ""
+    cam_file = str(config.get("move_camera_file",
+                    os.path.join("input", "move_camera.txt")))
+    cam_path = cam_file
+    if not os.path.isabs(cam_file):
+        cam_path = os.path.join(runtime_base, cam_file)
+    if not os.path.exists(cam_path):
+        return ""
+    import json
+    kfs = []
+    with open(cam_path, "r", encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if not line or line.startswith("#"):
+                continue
+            parts = line.split()
+            if len(parts) >= 4:
+                kfs.append([int(parts[0]), float(parts[1]),
+                            float(parts[2]), float(parts[3])])
+    return json.dumps(kfs) if kfs else ""
+
+
 def read_optional_index(data, key, default_value):
     """Read an optional integer index from structured txt metadata."""
     if key not in data:
@@ -257,7 +282,8 @@ def run_case(config_path, runtime_base, input_dir="input", output_dir="output",
                   "atom_radii": _fmt_alpha(data.get("atom_radii", [])),
                   "camera_distance": str(config.get("camera_distance", 40.0)),
                   "camera_elevation": str(config.get("camera_elevation", 0)),
-                  "camera_azimuth": str(config.get("camera_azimuth", 0))}
+                  "camera_azimuth": str(config.get("camera_azimuth", 0)),
+                  "camera_keyframes": _load_camera_kf(config, str(runtime_base))}
             
             n_frames = len(indices)
             compute.save_display_txt(