feat: make silence pause duration configurable via --pause flag

Default is 0.3s for responsive typing. Configurable on both
`cohere on --pause` and `cohere transcribe --stream --pause`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cohere_transcribe/daemon_main.py

@@ -4,5 +4,6 @@ from .daemon import run_daemon
 
 parser = argparse.ArgumentParser()
 parser.add_argument("--lang", default="en")
+parser.add_argument("--pause", type=float, default=None)
 args = parser.parse_args()
-run_daemon(args.lang)
+run_daemon(args.lang, pause=args.pause)