docs: Add comprehensive technology stack documentation

[openroomote-bruno]

This PR adds a detailed technology stack documentation file (STACK.md) that describes all the technologies, frameworks, libraries, and tools used in the VERT project.

What's included:

• Core Technologies: SvelteKit, Svelte 5, TypeScript
• Build Tools: Vite, Bun
• Styling: TailwindCSS, Sass, custom theming
• WebAssembly Engines: FFmpeg, ImageMagick, Pandoc
• UI Libraries: Lucide icons, OverlayScrollbars
• File Handling: Compression, metadata extraction, custom parsers
• i18n: Paraglide-js with 15 supported languages
• Deployment: Docker, Nginx configurations
• Development Tools: ESLint, Prettier, type checking
• Architecture Patterns: Web Workers, state management, converter system
• PWA Features: Service Worker, manifest

The documentation provides developers with a complete understanding of the project's technology choices and architecture patterns.

---

View task on Roo Code Cloud

[openroomote-bruno]

Rooviewer   Follow along on Roo Cloud

Reviewing your PR now. Feedback coming shortly!

[openroomote-bruno]

Rooviewer   See task on Roo Cloud

Review completed. The technology stack documentation is comprehensive, accurate, and well-structured. All version numbers match package.json, file paths are correct, and technical descriptions are accurate. No issues identified.

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}