feat(capture): toggle mouse pointer via capture.video.show_pointer (#691)

* feat(capture): toggle mouse pointer via capture.video.show_pointer

- config: register capture.video.show_pointer config option
- config: default pointer to visible (ShowPointer: true) on the
hardcoded fallback pipeline, override applies only when the flag is
explicitly set, so per-pipeline YAML overrides stay untouched
- compose: document NEKO_CAPTURE_VIDEO_SHOW_POINTER example

* fix(capture): apply show_pointer to all pipelines

- capture: thread capture.video.show_pointer into broadcast and
  screencast gstreamer pipelines, previously hardcoded show-pointer=true
  and silently ignored the flag
- config: resolve capture.video.show_pointer once into
  Capture.VideoShowPointer so all pipeline builders share one value
- docs: document capture.video.show_pointer in configuration/capture.md,
  including its reach into broadcast and screencast, and regenerate
  help.txt/help.json
- compose: drop stray commented-out example, default compose file is
  not meant to list every option

webpage/docs/configuration/capture.md

@@ -35,6 +35,7 @@ The Gstreamer pipeline is started when the first client requests the video strea
   "capture.video.ids",
   "capture.video.pipeline",
   "capture.video.pipelines",
+  "capture.video.show_pointer",
 ]} comments={false} />
 
 - <Def id="video.display" /> is the name of the [X display](https://www.x.org/wiki/) that you want to capture. If not specified, the environment variable `DISPLAY` will be used.
@@ -42,6 +43,7 @@ The Gstreamer pipeline is started when the first client requests the video strea
 - <Def id="video.ids" /> is a list of pipeline ids that are defined in the <Opt id="video.pipelines" /> section. The first pipeline in the list will be the default pipeline.
 - <Def id="video.pipeline" /> is a shorthand for defining [Gstreamer pipeline description](#video.gst_pipeline) for a single pipeline. This is option is ignored if <Opt id="video.pipelines" /> is defined.
 - <Def id="video.pipelines" /> is a dictionary of pipeline configurations. Each pipeline configuration is defined by a unique pipeline id. They can be defined in two ways: either by building the pipeline dynamically using [Expression-Driven Configuration](#video.expression) or by defining the pipeline using a [Gstreamer Pipeline Description](#video.gst_pipeline).
+- <Def id="video.show_pointer" /> overrides <Opt id="video.pipelines.show_pointer" /> for every video pipeline, only if explicitly set (per-pipeline `show_pointer` in `config.yaml` is left untouched when this flag is unset). It also controls the mouse pointer for the [Broadcast](#broadcast) and [Screencast](#screencast) pipelines, which do not have a per-pipeline setting of their own.
 
 ### Expression-Driven Configuration {#video.expression}
 

webpage/docs/configuration/help.json

@@ -192,6 +192,16 @@
     "defaultValue": {},
     "description": "pipelines config used for video streaming"
   },
+  {
+    "key": [
+      "capture",
+      "video",
+      "show_pointer"
+    ],
+    "type": "boolean",
+    "defaultValue": "true",
+    "description": "show mouse pointer in captured video, overrides show_pointer of all video pipelines"
+  },
   {
     "key": [
       "capture",

webpage/docs/configuration/help.txt

@@ -18,6 +18,7 @@
       --capture.video.ids strings                     ordered list of video ids
       --capture.video.pipeline string                 shortcut for configuring only a single gstreamer pipeline, ignored if pipelines is set
       --capture.video.pipelines string                pipelines config used for video streaming (default "{}")
+      --capture.video.show_pointer                    show mouse pointer in captured video, overrides show_pointer of all video pipelines (default true)
       --capture.webcam.device string                  v4l2sink device used for webcam (default "/dev/video0")
       --capture.webcam.enabled                        enable webcam stream
       --capture.webcam.height int                     webcam stream height (default 720)