feat: add channel allowlist

[anzzyspeaksgit]

Summary

Adds a --allow-channels / -a flag (and config field) to allow certain channels to bypass sponsor skipping logic entirely.

Problem

Closes #177
There was no way to allowlist channels you want to watch natively without skips.

Solution

Added AllowChannels to the config parsing. When processing segments for a video in watch.go, if d.meta.CurrArtist (which holds the channel name) matches any entry in the allowlist (case-insensitive), we skip evaluating d.segments entirely for that segment loop, allowing the video to play un-skipped.

Testing

• Verified config loads properly from env, flag, or config file via .golangci.yaml logic context.

---

This PR was created with AI assistance.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud