feat(api): stream one-generation graph construction sessions

[DecisionNerd]

Parent

Native sub-issue of #901. This issue must block #901 and does not expand its acceptance criteria.

Objective

Provide the ordinary Rust construction/import session used by large clients: accept bounded Arrow chunks durably, stage linearly, and publish exactly one immutable project generation.

Requirements

• Stream node then edge Arrow/Parquet batches through the feat(storage): stage topology append-only with linear ingest I/O #901 shard and UUID-surrogate primitives.
• Keep memory bounded by configured batch/shard/index-run limits.
• Persist deterministic resume markers and surrogate/index state.
• Validate duplicates and cross-kind conflicts with bounded external work.
• Commit graph, catalog, indexes, counters, and CURRENT once; abort/cancel/corruption leave the prior generation authoritative.
• Use this public path in the Graph500 ladder; do not loop publish_bulk_edges or add a benchmark-only writer.

Acceptance criteria

• Any number of accepted chunks produces exactly one final generation publication.
• Interrupted node and edge staging resumes without duplicate live rows; replay is idempotent.
• Cancellation, corruption, and validation failures preserve the prior CURRENT.
• Lower-scale tests prove fixed memory windows and linear work across increasing totals.
• S20/S22 evidence records per-window RSS, topology work rows, elapsed time, shard count, and physical disk.
• Full ordinary source to export to verify to clean import to reopen proof passes.

Non-goals

Distributed ingest, increased RAM ceilings, relaxed integrity, or benchmark-specific execution.