fix: Fortran engine use_marker/alpha header passthrough + case04 Moon orbit fix

- engines/fortran/main.f90:
  - 新增 use_marker 和 alpha_str 的读取、传递、写入 display.txt header
  - 新增 json_get_alpha 函数兼容 JSON 单值或 6 元数组
- engines/release/: 引擎校准缓存 & fortran.json 参数
- examples/case04/: 修正月球位置 (11.5→10.5) 和速度 (526→647),
  地月距缩至希尔半径以内 (0.5 < 1.0), 新增希尔半径验证说明
- examples/Readme.html: case04/case09 描述更新

engines/release/_calib_c.json

@@ -1 +1 @@
-{"n_atoms": 40, "nt": 10000, "step_time": 0.00015027170181274412}
+{"n_atoms": 40, "nt": 10000, "step_time": 3.113259077072144e-05}

engines/release/_calib_fortran.json

@@ -0,0 +1 @@
+{"n_atoms": 40, "nt": 200000, "step_time": 0.0002908185601234436}

engines/release/fortran.json

@@ -0,0 +1,51 @@
+{
+  "box_a": 300.0,
+  "NT": 200000,
+  "DT": 0.001,
+  "NSTEP": 100,
+  "warmup_steps": 0,
+  "method": "leapfrog",
+  "G": [
+    0.0,
+    0.0,
+    0.0
+  ],
+  "B": [
+    0.005,
+    0.0,
+    0.005
+  ],
+  "gravity_field": 0,
+  "gravity_interaction": 0,
+  "elastic_force": 1,
+  "damping_force": 0,
+  "gravity_strength": 1.0,
+  "driving_force": 1,
+  "save_trajectory": 0,
+  "alpha": [
+    0.0,
+    0.0,
+    0.0,
+    0.0,
+    0.0,
+    0.0
+  ],
+  "ball_radius": 0.5,
+  "ball_color": [
+    0.2,
+    0.6,
+    0.9
+  ],
+  "box_color": [
+    0.8,
+    0.8,
+    0.85
+  ],
+  "use_marker": 1,
+  "camera_distance": 60.0,
+  "camera_elevation": 0.0,
+  "camera_azimuth": 0.0,
+  "camera_center_x": 30.0,
+  "camera_center_y": 0.0,
+  "camera_center_z": 0.0
+}