rcdf 0.1.6

generate_pw(): switched from Mersenne Twister to a cryptographically secure RNG (openssl::rand_bytes).
write_parquet(): DuckDB errors no longer leak raw encryption key material in messages.
write_rcdf_parquet(): plaintext temp table is now always removed after a shared-connection write.
write_rcdf_as(): replaced eval(parse()) dispatch with a safe named-list of function references.
hex_to_raw(): added strict input validation (type, length, character set).

write_parquet() / write_rcdf_parquet(): removed httpfs overhead; shared DuckDB connection across writes; default compression changed to zstd.
read_rcdf(): new lazy = TRUE option for DuckDB-backed lazy reads; n_threads for parallel I/O; duplicate PRAGMA calls deduplicated per connection.
add_metadata(): label assignment vectorised with batch update.
open_duckdb_connection(): no longer forces single-threaded mode.

collect.rcdf_tbl_db(): fixed infinite-dispatch recursion; NULL metadata no longer causes an error.
read_parquet(): unencrypted early-return path now correctly applies metadata and as_arrow_table.
normalize_key_value(): hex keys no longer misidentified as base-64.

Main vignette rewritten for general/non-technical users with a step-by-step workflow.
Merging vignette completed and fixed.

rcdf 0.1.5

Added encrypt_value() and decrypt_value() functions, respectively, to encrypt and decrypt string using RSA.
Changed “dot env” (.env) reader from read_env() to read_dot_env().

Fixed bugs not returning metadata attributes using either read_rcdf() and get_rcdf_metadata().

Added get_attr() to retrieve attribute/s from RCDF object.
Added read_parquet_tbl() to read encrypted Parquet file and return as lazy data from DuckDB connection.

Added merge_rcdf() function to combine multiple RCDF files with different encryption keys into one.
Updated read_rcdf() to allow reading of multiple RCDF file with different encryption keys.
Added pre_collect argument to read_rcdf() to allow lazy loading the RCDF object.