When dependencies are not cached on the server (common since we removed
proactive caching), the dependency graph now:
- Continues resolving what it can find
- Shows missing dependencies in a separate section with amber styling
- Displays the constraint and which package required them
- Updates the header stats to show "X cached • Y not cached"
This provides a better user experience than showing an error when
some dependencies haven't been downloaded yet.
88765b4f50