Player Outline Through Blocks 1.0.0 for Minecraft 26.3

Initial 26.3 multi-loader build.

• Adds a configurable client-side outline for other players hidden by blocks.
• Includes separate production builds for Fabric, Forge, and NeoForge.
• Creates config/player_outline.json on first launch.
• Shows a bright outline around the player while keeping the skin and body fill hidden behind blocks.
• Tested with Afterburner 0.3.1 and Complementary Reimagined r5.9.3 on all three loaders.
• Shader-loader compatibility beyond the tested combination remains under evaluation; see the test report.