[Chore] Remove desktop app (Tauri) from project

[randomm]

Goal

Remove the Tauri desktop application from the project. We don't need it for oclite.

Scope

Packages to Remove

• packages/desktop/ - Tauri desktop wrapper

Related Cleanup

• Remove desktop-related scripts from root package.json
• Remove desktop build targets from any remaining CI/build scripts
• Update AGENTS.md monorepo structure section
• Remove any desktop-specific dependencies from root

Rationale

oclite is focused on:

• CLI/TUI experience
• Headless server mode (bun dev serve)
• Web app (if needed)

The Tauri desktop wrapper adds complexity without value for our use case.

Acceptance Criteria

• packages/desktop/ directory removed
• No references to desktop builds in scripts
• Documentation updated
• Build still works
• No orphaned dependencies

[randomm]

Fixed in PR #42. Removed packages/desktop/ (Tauri) - ~200 files deleted.