Add Combat HUD plugin

[upsetsingleevent]

Adds a compact, display-only HUD that floats above the local player showing:

• Buff timers (e.g. antifire, stamina, stat boosts) that flash when near expiry
• Attack cooldown in ticks, with automatic weapon-speed detection from the equipped item
• Spec indicator — a dot + energy % that lights up when the threshold is met

The plugin is strictly read-only. It reads game state (varbits, skill levels, equipment slot) and draws text/shapes via an overlay. It never injects input, modifies menus, sends clicks, or interacts with the game in any way.

[runelite-github-app]

New plugin combat-hud: https://github.com/upsetsingleevent/OSRSHUD/tree/d752333f4794ab71ea18fc843c690fee64d89f7b