Triple click to select whole lines gets stopped at channel mentions

Can reproduce CR - note: also occurs in text input bar, not just in existing messages - Canary Desktop 2026.913.210037, Web 2026.915.160715, Linux 6.16.12-valve24.5-1-neptune-616-gb2f7cfe85e45 (x64), Electron 44.1.1, Chrome 152.0.7977.65, Node 24.19.0, Locale en-US