Use stderr for informational output, stdout for transcription only

[gingerhendrix]

This PR modifies the output handling to:

• Use stderr for all informational/status messages
• Use stdout only for the final transcription output (text or JSON)

Changes:

1. Modified cli.ts to output only the transcription to stdout
2. Updated transcriber.ts to use stderr for status messages
3. Updated recorder.ts to use stderr for recording status messages

This makes it easier to pipe the output to other commands while still seeing status messages in the terminal.