{
    "success": true,
    "project": "N106",
    "from": "2026-06-01",
    "to": "2026-06-12",
    "ecm": "all",
    "ecm_total": 30,
    "source_table": "readings",
    "correction": {
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        "c2_offset_l": 300,
        "tank_max_l": 1000
    },
    "pricing": {
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        "c2_price_per_l": 0.12
    },
    "totals": {
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        "c2_usage": 0,
        "c1_cost": 0,
        "c2_cost": 0,
        "grand_total": 0
    },
    "rows": []
}