[Performance] Project Setup Slow - Dependencies Downloaded Every Time

[anshul23102]

Description

Project setup is slow because dependencies are downloaded fresh every time, even if already present locally. No caching of downloaded packages. Repeated dev environment setup takes 10-15 minutes.

Steps to Reproduce

1. First setup: devshell enter takes 12 minutes
2. Exit environment and re-enter
3. Second setup: again takes 12 minutes
4. No dependency caching between invocations

Environment Information

• Package manager: npm/pip/nix
• Caching: No cache mechanism
• Setup script: calls full download
• Network: Repeated downloads

Expected Behavior

• Dependencies cached locally
• Setup reuses cached packages
• Setup time: 2nd+ invocation < 30 seconds
• Smart invalidation when lockfile changes

Actual Behavior

• All downloads happen every setup
• No caching
• Setup always takes 10-15 minutes
• Wasted bandwidth

Code Reference

• File: src/devshell/setup.sh
• Method: install_dependencies() - no cache check
• Missing: Local cache directory
• Missing: Cache validation

Additional Context

Level 2 performance issue. Fix requires:

• Implementing local package cache
• Adding cache invalidation logic
• Benchmarking: would reduce setup to <30s
• Documenting cache location

Suggested Labels

performance, optimization, caching, developer-experience, installation