docs planning RUST_STATION_INGESTION_RST11

RST-11 — Representative datasets and geographic request distributions

Status: IMPLEMENTED — offline synthetic generation only; no network, no database, no national fetch. Date: 2026-10-09. Scope: RUST_STATION_BENCHMARK_PLAN.md RST-11, dependency RST-10 (PROTOCOL_FROZEN). Language: English document; user communication in Portuguese.

B-BR/BUC: B-BR-RST-P02 (reproducible inputs: pinned seeds, byte hashes, oracle counts), B-BR-RST-P05 (fair geographic coverage: uniform/proportional/skew/hot traces with empty strata reported), B-BR-RST-P06 (useful evidence: machine-readable oracle/trace JSON, no invented rows). Serves BUC-RST-P01 (clean full import inputs) and BUC-RST-P05 (regression oracle).

1. What was added

• tools/station-prep/src/datasets.rs (station-datasets-v1): deterministic generator over a frozen 200-city universe (CIDADE 000..199, IBGE 3550000+i, UF SP) plus 5 zero-row cities (VAZIA 000..004, IBGE 3559900+i). Same xorshift64* RNG and checksum-valid CNPJ recipe as the RST-07 pilot, with [RST11-TEST] markers so the multiset hash differs by label while accounting stays comparable.
• Frozen profiles: tiny (30 rows, seed 11, 5 cities, all knobs on), representative (20k, seed 7, RST-07 skew), stress-100k and stress-1M (seed 7, scratch only, never committed). Independent knobs: duplicate/conflict percentages, every-N quarantine injection (alternating invalid-CNPJ / unknown-city), every-N long fields, every-N missing sidecar locations, changed/no-op delta editions (delta_edition), history cardinalities 1/10/100 as oracle counts over the explicit unique-station denominator.
• Independent oracle per dataset: input/accepted/duplicates/ quarantined reconciliation, unique CNPJs, per-city histogram, multiset checksum (bench_parse recipe), CSV SHA256, history and location counts. Sidecar locations are labelled synthetic with no reviewed flag by construction; missing points are explicit.
• Frozen request traces (W-<profile>-<uniform|proportional| skew-80-20|hot-90>): largest-remainder apportionment summing exactly to the requested total; pool shares (80/20, 90/10) independent of universe size; empty cities listed with zero stations, never invented. Strata empty/1–10/11–100/>100.
• src/bin/bench_datasets.rs: emits CSV plus --aliases, --oracle and --trace artifacts to scratch. The RST-07 bench_generate/bench_parse pair is untouched.
• Committed correctness set contracts/testdata/station-prep/datasets/: tiny.csv, tiny-aliases.json, tiny-oracle.json, trace-uniform-1000.json.
• Tests: 5 unit + 10 integration (tests/datasets.rs), including a committed-fixture pin (regeneration reproduces committed bytes; real parser agrees with the on-disk oracle).

2. Evidence

• cargo fmt --check, cargo clippy --all-targets -- -D warnings, cargo test --locked: 12 lib + 35 integration cases pass (parser 9, join 9, deltas 9, datasets 10, plus unit/doc bins); cargo audit: 25 locked crates, no findings.
• Tiny oracle (frozen): input 30, accepted 24, duplicates 2, quarantined 4 (2 invalid-CNPJ + 2 unknown-city), unique 24, checksum ebe47c28b9cc0d0601bc042c36beae62bb4145f1f29edd36f07220b820e24844, CSV SHA256 507cf466ccbd6c71f5f1f743aeb91be068b662ef5c35582c095c50b6013bedd9 (4973 bytes). History 24/240/2400; locations 20 present + 4 missing. Reordered input parses to identical counts/checksum.
• Representative 20k (seed 7, debug, 0.126 s): 19552/430/18, checksum b6fb02070bf1a681d76462adcbcc557fb1feb6dde09560158d52563224353f64.
• Stress-100k (seed 7, debug, 0.695 s): 98004/1996/0 — identical accounting to the RST-07 pilot, confirming the shared shape family (multiset hash differs by [RST11-TEST] labelling only).
• Observed skew (reported, not tuned): 20k rows populate 27/200 cities, densest holds ~50%; empty/unpopulated strata stay listed with zero stations. Uniform trace covers zero-row cities (500/1000 requests to empties at 10 cities); proportional keeps explicit zero weight for them.
• Reproduce: cargo run --locked --bin bench_datasets -- tiny /tmp/tiny.csv --aliases /tmp/aliases.json --oracle /tmp/oracle.json --trace uniform 1000 /tmp/trace.json.

3. Limits and next task

• No DB seeding, load harness, or measured query latency here; those belong to RST-12/14 with their own evidence. The 1M profile is frozen but not executed in this task. PMQC assay history is represented as oracle cardinalities only. No contributor GPS, production photos, credentials or live sources anywhere.
• Next (smallest, separately authorized): RST-12 measurement harness and instrumentation qualification.