## 1. Dependencies

- [ ] 1.1 Add github.com/Jguer/dyalpm to go.mod
- [ ] 1.2 Run go mod tidy to resolve dependencies

## 2. Pac Struct Updates

- [ ] 2.1 Add dyalpm handle field to Pac struct
- [ ] 2.2 Add package info cache field (map[string]PackageInfo) to Pac struct
- [ ] 2.3 Update New() to initialize dyalpm handle
- [ ] 2.4 Update Close() to release dyalpm handle

## 3. ValidatePackage Implementation

- [ ] 3.1 Implement ValidatePackage using dyalpm LocalDB().Pkg()
- [ ] 3.2 Query sync databases if not found locally
- [ ] 3.3 Add caching logic to store/query results
- [ ] 3.4 Keep AUR fallback for packages not in pacman repos

## 4. MarkExplicit Updates

- [ ] 4.1 Change MarkExplicit signature to accept []string (slice of packages)
- [ ] 4.2 Implement single pacman -D --explicit call with all packages
- [ ] 4.3 Handle empty slice case (return nil immediately)

## 5. Call Site Updates

- [ ] 5.1 Update Sync() to pass packages slice to MarkExplicit
- [ ] 5.2 Ensure categorizePackages works with new ValidatePackage

## 6. Testing

- [ ] 6.1 Run existing tests to verify no regressions
- [ ] 6.2 Test ValidatePackage with local, sync, and AUR packages
- [ ] 6.3 Test MarkExplicit with single and multiple packages
- [ ] 6.4 Verify cache behavior (second call returns cached result)