vecrep 0.1.0

• rep_altrep() replicates vectors using R’s ALTREP framework, storing only a reference to the original data rather than copying full expanded replicates into memory.
• Supports double, integer, logical, complex, raw, character, and list vectors (list support requires R >= 4.2).
• Preserves classes and attributes (e.g. factor, Date, POSIXct) for correct S3 dispatch.