## Why

CB channel 16 (27.155 MHz) is commonly used for regional traffic and is worth monitoring alongside the existing channels 3, 7, and 10. The frequency already falls within the current SDR sample window, so adding it requires only a configuration change.

## What Changes

- Add CB channel 16 (27.155 MHz) as a new monitored channel in `rtl_airband.conf`
- Uses the same NFM modulation, bandwidth, squelch, and file output settings as existing channels
- Recordings saved with `CB_CH16_27155` filename template

## Capabilities

### New Capabilities
- `cb-channel-16-monitoring`: Monitor and record transmissions on CB channel 16 (27.155 MHz)

### Modified Capabilities

_(none — existing channel monitoring is unchanged)_

## Impact

- `rtl_airband.conf`: New channel entry added to the existing device's channel list
- No changes to Docker, Nginx, or cleanup configuration needed
- No additional hardware or SDR tuning changes required (27.155 MHz is within the current 2.4 MHz sample window)