Honor bread.command.shot.region via breadshot listen

Pin bread-utils to bread-ecosystem v0.7.2. breadshot listen
subscribes to bread.command.shot.**, runs the same region capture
as the CLI (clipboard-only), and emits bread.shot.region.done /
.failed.

README.md

@@ -47,8 +47,14 @@ make install PREFIX=/usr
 
 ```
 breadshot <mode> [options]
+breadshot listen
 ```
 
+`breadshot listen` is the long-running process that honors
+`bread.command.shot.region` on the bread event bus (clipboard-only
+region capture). See [EVENTS.md](EVENTS.md). Without it, the CLI still
+works; bus commands are a silent no-op.
+
 ### Modes
 
 | Mode | Description |