[table] Support reading dedicated and rolling (multi-segment) vector files

[JunRuiLee]

Purpose

Add read-path support for dedicated .vector.<format> files in data-evolution splits, including rolling (multi-segment) vector columns. Upstream Paimon's DedicatedFormatRollingFileWriter rolls a vector column into multiple .vector. segments (using an independent VECTOR_TARGET_FILE_SIZE), so the Rust reader needs to consume such tables by reassembling the segments. This mirrors upstream's VectorFileBunch non-pushdown semantics in DataEvolutionSplitRead.java.

Changes

All changes are confined to the read path (crates/paimon/src/table/data_evolution_reader.rs).

• Classify & route vector files: is_vector_store_file_name detector; normalize_merge_group classifies .vector. files into their own group, excludes them from the merge anchor, and forces the column-merge path.
• VectorBunch (modeled on the existing BlobBunch): aggregates rolled segments belonging to one logical vector source, keyed by (schema_id, format_suffix, normalized_write_cols). add enforces continuity/dedup (same-first_row_id lower-seq -> ignore, overlap lower-seq -> ignore, gap -> error, row-count overflow -> error, key-identity mismatch -> error).
• Segment ordering: normalize_merge_group sorts vector segments by first_row_id asc, then max_sequence_number desc, and no longer validates rolled segments (which are slices) against the normal-file row range.
• normalized_write_cols: computed per vector file in load_file_infos (write columns sorted by field position; missing write_cols -> DataInvalid), so differently-ordered raw write columns that normalize equal aggregate into one bunch.
• build_source_plan: aggregates same-key segments into a single FieldSource::VectorBunch, with a bunch-granularity duplicate-field-id guard and a bunch row-count check symmetric to the blob check. A single vector file is simply a bunch of length 1 -- one code path, no special-casing.
• Read: VectorBunch is read via the same sequential-concat path as BlobBunch; each segment carries its real first_row_id/row_count, so the existing to_local_row_ranges mechanism clips absolute row ranges per segment correctly.

Out of scope

Write-side changes; blob fallback-placeholder optimization; predicate/vector pushdown into vector files; upstream's rowIdPushDown branch (non-pushdown semantics only).

Tests

• Unit: VectorBunch::add guards (gap / overlap-lower-seq / same-first_row_id dedup / row-count overflow / key-identity mismatch); normalize_merge_group multi-segment sort and removal of the vector range check; normalize_vector_write_cols sort-by-position and missing/unknown-column errors; build_source_plan aggregation (incl. differently-ordered write cols collapsing to one bunch) and cross-bunch duplicate-field-id rejection.
• Integration (end-to-end): normal data.parquet + 3 rolled .vector.parquet segments reassemble into the correct column in order (including a null row); row_ranges selecting rows across a segment boundary return the correct subset.

All 41 data_evolution_reader tests pass; clippy clean.

Note: this builds on the earlier dedicated-vector classification/routing commits; the diff against main includes those as they have not yet landed upstream.

[JingsongLi]

+1