Analyze this codebase and create a multi-level interactive dependency graph visualization as a single HTML file.
Level 1 - System Overview (40,000ft view):
- Show only top-level directories/subsystems
- Group by: Frontend, Backend, Core, Database, Tests, Tools, External
- Display as large nodes with # of files and primary language
- Show only major connections between subsystems
Level 2 - Module View (10,000ft view):
- Show ~30-50 most important modules/packages