feat(harness): port backend Onda 0 — vendor, lshindex, sqlcheck, execute, rest/exec, ctetest, report, datamart

8 moduli leaf portati verbatim da ChironeWp3 con rename psdwp3→tht:
- vendor/thoth_lsh (MinHash/LSH, leaf puro datasketch+tqdm) + VENDORED.md
- lshindex/ (build/save/load/query, dipende vendor + LshConfig)
- sqlcheck/ (validate_sql, leaf ExecutionConfig+mschema)
- execute/ + execute/warnings (run_controlled/explain, leaf sqlglot+sqlalchemy)
- rest/execute + rest/explain (REST variants, dipendono execute+rest.client)
- ctetest (CTE test records, leaf sqlglot+pydantic)
- report (validation report rendering, dipende execute+sqlcheck)
- datamart (stub NotImplementedError)

Verifica: import smoke catena completa OK, pytest 109 passed. Deps (datasketch, sqlglot,
sqlalchemy, pydantic, requests, tqdm) già in pyproject. VENDORED.md neutralizzato
(riferimenti PsdWp3→Thoth).

harness/tht/report.py

@@ -0,0 +1,74 @@
+from tht.execute import ExecResult, PlanSummary
+from tht.sqlcheck import CheckResult
+
+NOTE_HEADING = "## Note del reviewer"
+
+
+def _markdown_table(columns: list[str], rows: list[tuple]) -> str:
+    lines = [
+        "| " + " | ".join(columns) + " |",
+        "|" + "---|" * len(columns),
+    ]
+    for row in rows:
+        lines.append("| " + " | ".join(str(v) for v in row) + " |")
+    return "\n".join(lines)
+
+
+def render_validation_report(
+    *,
+    session_id: str,
+    check: CheckResult,
+    plan: PlanSummary,
+    plan_warnings: list[str],
+    result: ExecResult,
+    runtime_warnings: list[str],
+    static_warnings: list[str],
+    limit: int,
+    reviewer_notes: str = "",
+) -> str:
+    """Sezioni fattuali del validation report. La sezione note e' di Pi/reviewer:
+    se gia' scritta, va passata in reviewer_notes per preservarla."""
+
+    def warn(ws: list[str]) -> str:
+        return "\n".join(f"- warning: {w}" for w in ws) if ws else "- nessun warning"
+
+    parts = [
+        f"# Validation report — {session_id}",
+        "",
+        "> Avvertenza: questo report contiene sample di dati del database.",
+        "",
+        "## Parsing e read-only",
+        "",
+        "- parsing: OK" if check.ok else "- parsing: ERRORI",
+        "- statement read-only per struttura: OK" if check.ok else
+        "\n".join(f"- ERRORE: {e}" for e in check.errors),
+        warn(check.warnings + static_warnings),
+        "",
+        "## Piano di esecuzione",
+        "",
+        f"- costo totale stimato: {plan.total_cost}",
+        f"- righe stimate: {plan.plan_rows}",
+        f"- nodi: {', '.join(plan.node_types)}",
+        warn(plan_warnings),
+        "",
+        "## Preview / aggregato",
+        "",
+        f"- tempo di esecuzione: {result.execution_ms} ms (limit {limit})",
+        "",
+        _markdown_table(result.columns, result.rows),
+        "",
+        warn(runtime_warnings),
+        "",
+        NOTE_HEADING,
+        "",
+        reviewer_notes.strip(),
+        "",
+    ]
+    return "\n".join(parts)
+
+
+def extract_reviewer_notes(report_md: str) -> str:
+    """Estrae il contenuto della sezione note da un report esistente."""
+    if NOTE_HEADING not in report_md:
+        return ""
+    return report_md.split(NOTE_HEADING, 1)[1].strip()