declpac/openspec/changes/use-dyalpm-and-batch-explicit/tasks.md

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)