refactor(effects-manager): extract GLSL shaders to TypeScript modules (#886)

[deveshbervar]

Summary

Phase 2a of the refactoring proposed in #886.

Extracts the two inline GLSL shader strings fromeffects-manager.ts into dedicated TypeScript modules.

What changed

New files:

• shaders/hover-vertex.ts — vertex shader as TS default export
• shaders/hover-fragment.ts — fragment shader as TS default export

Modified:

• effects-manager.ts — imports shaders from modules instead of defining them as inline class properties

Why TypeScript modules instead of .glsl files

Previous attempt (#933) used .glsl files with raw-loader but hit esbuild/Angular build pipeline issues in the Docker
smoke test. TypeScript modules work natively with all three build tools (webpack, esbuild, Jest) with zero configuration
changes.

Scope

• 2 new files, 1 modified file
• Zero behavior change — shaders are identical
• All 25 effects-manager tests pass
• Part of refactor: EffectsManager missing state model, hover color not configurable, no experiment override API #886 — Phase 2, PR 2a