docs: clarify unaligned depth topic conditions

docs/en/source/camera_devices/4_application_guide/topics.md

@@ -26,7 +26,7 @@ These topics provide the raw image data and corresponding calibration informatio
     *   Low-level metadata from the depth stream firmware.
 *   `/camera/depth/image_unaligned`
     *   Depth image before software alignment.
-    *   **Condition:** Published when `depth_registration` is `true` and `align_mode` is `SW`; it is not published for hardware alignment.
+    *   **Condition:** Published only when `depth_registration` is `true`, `align_mode` is `SW`, and the alignment target is `COLOR` (software D2C); it is not published for software C2D or hardware alignment.
 *   `/camera/confidence/image_raw`
     *   Confidence image generated by `EnhancedDepthFilter`, encoded as `mono8` or `mono16` according to the confidence frame format.
     *   **Condition:** Published when enhanced depth filtering succeeds and the topic has a subscriber.

docs/en/source/camera_devices/5_advanced_guide/configuration/align_depth_color.md

@@ -34,6 +34,8 @@ After the camera node starts, use `/camera/set_image_registration_mode` to switc
 
 Both color and depth streams must be enabled for every mode except `OFF`. The service stops and restarts streams automatically during the switch and restores the previous mode if the operation fails.
 
+When `depth_registration` is enabled, only `SW_D2C` publishes `/camera/depth/image_unaligned`; `SW_C2D` does not publish this topic.
+
 ```bash
 ros2 service call /camera/set_image_registration_mode orbbec_camera_msgs/srv/SetString "{data: SW_D2C}"
 ```

docs/en/source/camera_devices/5_advanced_guide/configuration/enhanced_depth_filter.md

@@ -106,7 +106,7 @@ The following topic names assume the default `camera_name:=camera`. If `camera_n
 | Topic | Description |
 | --- | --- |
 | `/camera/depth/image_raw` | Publishes the enhanced aligned depth image when filtering succeeds. If filtering fails at runtime, the driver continues to publish the current unenhanced aligned depth image. |
-| `/camera/depth/image_unaligned` | Publishes the depth image before software alignment. This topic is not published in hardware D2C mode. |
+| `/camera/depth/image_unaligned` | Publishes the depth image before alignment only for software D2C (`align_mode:=SW` and `align_target_stream:=COLOR`). It is not published for software C2D or hardware D2C. |
 | `/camera/confidence/image_raw` | Publishes the confidence image with `mono8` encoding when filtering succeeds. |
 
 ## Check the Runtime Status