feat: add --normalize compressor + limiter for input audio

Adds a feedforward dynamic range compressor with a brick-wall limiter
applied in the audio callback. Quiet speech gets +12 dB makeup gain,
loud bursts are attenuated 4:1 above -20 dBFS, and the output is
hard-limited at -1 dBFS so nothing clips. Enabled via --normalize/-n
on `cohere on` and `cohere transcribe`.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/cohere_transcribe/cli/cli.py

@@ -26,6 +26,7 @@ def on(
     language: str = typer.Option("en", "--lang", "-l", help="Language code"),
     pause: float = typer.Option(0.3, "--pause", "-p", help="Seconds of silence before sending text"),
     device: str = typer.Option(None, "--device", "-d", help="Input device index or name substring (see `cohere devices`)"),
+    normalize: bool = typer.Option(False, "--normalize", "-n", help="Enable compressor + limiter to even out loudness"),
     foreground: bool = typer.Option(False, "--fg", help="Run in foreground (don't daemonize)"),
 ):
     """Start transcribing and typing into your focused window."""
@@ -36,7 +37,7 @@ def on(
     if foreground:
         from ..daemon import run_daemon
         console.print("[green]Starting cohere (foreground)...[/green]")
-        run_daemon(language, pause=pause, device=_parse_device(device))
+        run_daemon(language, pause=pause, device=_parse_device(device), normalize=normalize)
         return
 
     console.print("[green]Starting cohere daemon...[/green]")
@@ -46,6 +47,8 @@ def on(
         cmd += ["--pause", str(pause)]
     if device is not None:
         cmd += ["--device", device]
+    if normalize:
+        cmd += ["--normalize"]
     subprocess.Popen(
         cmd,
         start_new_session=True,
@@ -103,6 +106,7 @@ def transcribe(
     language: str = typer.Option("en", "--lang", "-l", help="Language code"),
     pause: float = typer.Option(0.3, "--pause", "-p", help="Seconds of silence before sending text"),
     device: str = typer.Option(None, "--device", "-d", help="Input device index or name substring (see `cohere devices`)"),
+    normalize: bool = typer.Option(False, "--normalize", "-n", help="Enable compressor + limiter to even out loudness"),
 ):
     """One-shot transcription (file, mic, or stream to terminal)."""
     from ..model import load_model, transcribe_audio
@@ -113,12 +117,12 @@ def transcribe(
     if stream:
         from ..stream import stream_transcribe
         processor, model = load_model()
-        stream_transcribe(processor, model, language, silence_frames=pause_seconds_to_frames(pause), device=dev)
+        stream_transcribe(processor, model, language, silence_frames=pause_seconds_to_frames(pause), device=dev, normalize=normalize)
     elif mic is not None:
         from ..model import record_audio
         processor, model = load_model()
         try:
-            audio = record_audio(mic, device=dev)
+            audio = record_audio(mic, device=dev, normalize=normalize)
             console.print("Transcribing...")
             text = transcribe_audio(processor, model, audio, language)
             console.print(f"\n{text}\n")