feat: global documentation & git lfs

[Floffah]

No description provided.

[Copilot]

Pull Request Overview

This PR restructures the documentation infrastructure by moving VitePress from the backend to the repository root, establishing a centralized documentation site. It also adds game assets via Git LFS, updates dependencies, and improves CI workflow efficiency.

• Centralized documentation setup with VitePress at root level
• Added comprehensive authentication flow documentation with Mermaid diagrams
• Integrated game story/music documentation and Git LFS for binary assets
• Updated dependencies and improved CI workflow path filtering

Reviewed Changes

Copilot reviewed 15 out of 25 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
package.json	Moved VitePress configuration to root workspace, added documentation scripts and Mermaid dependencies
.npmrc	Added public-hoist-pattern for VitePress peer dependencies
docs/.vitepress/config.ts	Created VitePress configuration with navigation and sidebar for backend reference and game documentation
docs/backend-reference/flows/authentication.md	Added comprehensive authentication flow documentation with sequence diagrams
docs/game/story.md	Added game story and world overview documentation
docs/game/music.md	Added music documentation and identity
backend/package.json	Removed VitePress-related scripts and dependencies, updated package versions
.gitattributes	Configured Git LFS for media files (mp3, wav, gltf, glb, pdf)
.github/workflows/godot-ci.yml	Added path filtering to only run on game directory changes
game/models/**/*.glb & game/models/player/eform.gltf	Added game models via Git LFS