pavdata 0.1.0

First public release of pavdata.

• Introduces S3 classes for pavement samples, binders, aggregates, mixtures, material tests, and references.
• Provides constructors, validation, relational-integrity checks, and an in-memory library for querying PavData objects.
• Supports reading and writing the human-readable .pavdata format.
• Provides print(), summary(), and plot() methods for PavData objects and libraries.
• Includes an example dataset with 296 Brazilian asphalt mixture records.
• Includes tests, documentation, citation metadata, and a repository README.