Healt Alert Tweaks

Healt Alert Tweaks - 1.21.6 - 1.21.8

Merged compatibility build for Minecraft 1.21.6, 1.21.7, and 1.21.8.

Changed

• Added support for Minecraft 1.21.6.
• Added support for Minecraft 1.21.7.
• Added support for Minecraft 1.21.8.
• Merged the compatible versions into one build range.
• Updated dependency targets for the 1.21.6+ compatibility line.

Technical

• Vignette rendering logic remains unchanged.
• Heartbeat sound timing and low-health integration remain unchanged.
• Mod Menu configuration behavior remains unchanged.
• Compatible versions were merged because no relevant client API changes required separate code paths.