Add ParquetExporter (Vortex -> Parquet) - #362

Inverse of ParquetImporter, built on Hardwood 1.1's new ColumnWriter/
ParquetFileWriter write API. Flat schemas only: Bool, non-F16
Primitive, Utf8, Binary, and vortex.timestamp (MILLIS/MICROS/NANOS);
Struct/List/Map top-level columns throw UnsupportedOperationException.

- Bumps dev.hardwood:hardwood-core 1.0.0.Final -> 1.1.0.Beta1 (adds the
  write API this depends on, plus read-path speedups for ParquetImporter).
- ParquetExporter / ExportOptions in the parquet module, mirroring
  ParquetImporter/ImportOptions' shape.
- vortex-reader promoted from test- to production-scope dependency in
  parquet/pom.xml.
- ParquetExporterTest: type-mapping unit tests, flat export + projection
  + unsupported-type integration tests, and two round-trip tests
  (Vortex -> Parquet -> Vortex via ParquetImporter) covering flat types
  (including U8/U32 boundary values) and the timestamp extension.
- CLI: the `export` subcommand now dispatches to ParquetExporter when the
  output path ends `.parquet` (previously CSV-only); usage text and
  ExportCommandTest updated.
- Remote HTTP(S) support, both directions:
  - ParquetExporter.exportParquet(VortexHandle, Path[, ExportOptions]):
    exports an already-open handle (local VortexReader or remote
    VortexHttpReader) without an intervening local copy; the handle is
    not closed here, the caller keeps ownership.
  - ParquetImporter.importParquet(URI, Path[, ImportOptions]): imports a
    Parquet file served over HTTP(S), fetched entirely through targeted
    Range requests via the new HttpInputFile (implements Hardwood's
    InputFile), mirroring VortexHttpReader's own range-fetch pattern. No
    full-file download occurs.
  - checkNoDuplicateNames/fillRow take a String sourceName instead of a
    Path, since a remote source has no filesystem path to report in
    error messages.
  - CLI: `export`/`import` accept a url source too (Parquet-only in both
    directions; CSV and stdout streaming from a URL are out of scope).
  - HttpInputFileTest covers the HEAD/Range request mechanics against a
    mocked HttpClient. Live-verified end to end against a real ~3M-row
    public Parquet file (NYC taxi trip data) via the built CLI jar:
    remote Parquet -> local Vortex -> local Parquet -> reimport, with
    row counts and min/max stats matching exactly at every step.
- docs/reference.md, docs/how-to.md: document the new class/options, the
  remote overloads, and the CLI's Parquet import/export support.
- DocsConsistencyTest: allowlist WriterConfig as a known external
  receiver cited in reference.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LjU7zWghUiJauRxK58nyUs