test: lock speechbrain lengths and identity camera filter

Filter --cameras 1,5 by cam-NN identity instead of discovery index.

run.py

@@ -21,7 +21,7 @@ import time
 from pathlib import Path
 
 from config import load_config, _load_dotenv
-from discovery import discover_cameras
+from discovery import discover_cameras, select_cameras
 from tokens import make_token
 
 log = logging.getLogger("cameras.main")
@@ -126,12 +126,10 @@ def main() -> int:
                  c.audio_card if c.audio_card is not None else "-",
                  c.usb_port or "-")
 
-    if cfg.cameras != ["all"]:
-        wanted = set(int(i) - 1 for i in cfg.cameras)
-        cameras = [c for c in cameras if c.index in wanted]
-        if not cameras:
-            log.error("no cameras match --cameras %s", args.cameras)
-            return 2
+    cameras = select_cameras(cameras, cfg.cameras)
+    if not cameras:
+        log.error("no cameras match --cameras %s", args.cameras)
+        return 2
 
     sup = Supervisor(cfg, cameras)
     for cam in cameras: