Shader graph update

[Kyonru]

• Standalone Showcase build for trying Shader Graph and Particle System Playground in the browser without connecting a game.
• Static love.js preview bridge for standalone shader and particle previews, including showcase build/preview scripts and a publishing workflow.
• Shader Graph custom function, texture input, texture uniform color, texture upload, and preview texture support.
• Expanded Shader Graph node library with complex math, quaternion operations, symmetry, random, pixel-perfect primitives, patterns, halftone, Lab color helpers, composite, Truchet tiles, improved SDF nodes, and broader vertex shader authoring.
• Shader Graph preset and UI improvements for graph authoring, node inspection, code preview, and standalone preview controls.
• Session Replay checkpoints, seeking, baseline restore, sparse state deltas, and Lua E2E coverage for replay flows.
• Add sub graph
• Add option to copy and paste nodes
• Add external params
• Pre-push hook that runs CLI E2E, Lua E2E, app Playwright E2E, and showcase Playwright E2E before pushing.