Use this first whenever the user mentions a specific shipment or order.

Args:
    shipment_id: Shipment ID such as "SHP-1001" (also accepts "shp1001" or "1001").

Returns:
    The shipment (status, priority, origin_city, destination_city, last_city, eta, promised_by,
    is_late, delay_hours, hours_to_promise, carrier_name, vehicle, customer, weight_kg, notes)
    plus ``recent_events`` (latest 5, newest last). On a miss: status="error" with suggestions.

Args:
    status: One of created, picked_up, in_transit, delayed, out_for_delivery, delivered, exception,
        or "active" (anything not yet delivered/exception). Empty = all.
    city: City name or alias (e.g. "Bangalore", "Bombay"); matches origin, destination or current city.
    priority: standard, express or critical. Empty = all.
    limit: Maximum rows to return (default 25).

Returns:
    {"status": "ok", "count": n, "shipments": [...]} each with is_late / delay_hours.

Args:
    shipment_id: Shipment ID such as "SHP-1003".

Returns:
    {"status": "ok", "shipment_id": ..., "events": [{ts, status, city, note, source}, ...]}.

Args:
    shipment_id: Shipment ID such as "SHP-1002".
    status: New status: created, picked_up, in_transit, delayed, out_for_delivery, delivered or exception.
    city: Optional city where the update happened (defaults to the current/destination city).
    note: Short human-readable reason, e.g. "Rain on NH-48, 6h delay". Stored as the shipment note.

Returns:
    {"status": "ok", "previous_status": ..., "shipment": {...}, "event": {...}} or an error with valid values.

Args:
    sku: SKU ID ("SKU-107") or product name fragment ("insulin", "gloves"). Empty = all SKUs.
    warehouse_id: Warehouse ID ("WH-BLR"), code ("BLR") or city ("Bangalore"). Empty = all warehouses.
    low_stock_only: If true, only lines at or below their reorder point.

Returns:
    {"status": "ok", "count", "low_stock_count", "items": [{sku, name, warehouse_id, qty_on_hand,
    reorder_point, shortfall, low_stock, open_po, ...}]}.

Args:
    sku: SKU ID such as "SKU-107".
    warehouse_id: Warehouse ID ("WH-BLR"), code or city.
    qty: Units to order; 0 = automatic (tops stock up to 2x reorder point, min standard reorder qty).

Returns:
    {"status": "ok", "duplicate": bool, "purchase_order": {id, qty, supplier, expected_by, ...}, "message"}.

Args:
    status: available, on_route or maintenance. Empty = all.
    city: Current city of the vehicle (name or alias). Empty = all.

Returns:
    {"status": "ok", "count", "vehicles": [{id, type, capacity_kg, remaining_capacity_kg, status,
    current_city, driver_name, driver_hours_today, driver_hours_remaining, fuel_pct, refrigerated}]}.

Args:
    shipment_id: Shipment ID such as "SHP-1007".
    vehicle_id: Vehicle ID such as "TRK-105".

Returns:
    {"status": "ok", "warnings": [...], "vehicle": {...}} - warnings flag soft issues (vehicle in another
    city, driver near the 10h limit, low fuel, cold-chain mismatch). Errors suggest alternative vehicles.

Returns:
    {"status": "ok", "count", "carriers": [...]}.

Returns:
    {"status": "ok", "count", "warehouses": [...]}.

Returns:
    KPI dict with status="ok".