Release v1.2.3

• Audio: Added "Output Audio Mode" setting to choose which audio sources are captured (all PC audio, game only, or game + Discord). Closes #43.
• Settings: Added a "Default Device" option that follows the OS default audio endpoint for automatic switching. Closes #74.
• Recording: Reset the replay buffer after saving a clip. Closes #49.
• UI: Fixed video player overflowing the window height on ultrawide monitors. Closes #105.
• UI: Improved waveform rendering while zooming the timeline.
• Startup: Fixed a bug where opening a second instance killed the first instead of bringing it to the foreground.