v0.2.0

Added

• batch convert command: recursive, multi-threaded NetCDF → Parquet conversion
• batch header command: recursive, multi-threaded NetCDF → YAML conversion
• header command: single-file NetCDF → YAML metadata extraction
• --pattern option on all batch subcommands for filename-based file selection (glob, per-subcommand default)
• --output, --threads options on all batch subcommands
• All config fields exposed as individual CLI flags on convert and batch convert; priority: built-in default < --config file < CLI flags
• profile_longitude / profile_latitude columns in NRT output (from PRECISE_* or expanded DEPLOY_*)
• Unit tests for pure logic functions (no fixture files required)

Changed

• QC flag columns changed from i8 to String; non-numeric codes (e.g. "A", "B") are preserved; missing values become ""
• Source tree reorganised: src/netcdf/ → src/convert/; header modules moved to src/header/
• NRT and CORA converters unified into single modules with TOML config files