Active cards with available balance and owner names

# Instructions

## Use case

List active cards with their available balance and identify the owner for each card.

## Basic call

```json
{
  "companyId": "<COMPANY_ID>",
  "status": "ACT",
  "pageSize": 50
}
```

Note: unlike `get_purchase_orders.status` which takes an **array**, `list_cards.status` takes a **plain string** (a single status at a time).

## Card lifecycle

```
PRE (pre-active) → ACT (active)
ACT → BLO (blocked)
BLO → REA (reactivated) → ACT
```

Terminal states (cannot return to active): `LOS`, `STO`, `DAM`, `EXP`, `CAN`, `CMD`

To list active cards in the broad sense, target `ACT` and `REA`:
- `status: "ACT"` — active
- `status: "REA"` — reactivated (after blocking)

## Critical pitfall — availableBalance.amount is a DECIMAL, not a coefficient

**All other Spendesk responses** return `amount` as an integer coefficient:
`{ amount: 9138, precision: 2 }` → 91.38 EUR

**`list_cards.availableBalance.amount` returns the DECIMAL value directly:**
`{ amount: 91.38, currency: "EUR", precision: 2 }` → 91.38 EUR (not 9138!)

→ Never apply `amount / 10^precision` to `availableBalance.amount` from `list_cards` — the result would be 100x too small.

```javascript
// CORRECT for list_cards.availableBalance
const balance = card.availableBalance.amount  // 91.38 EUR directly

// CORRECT for all other tools (get_payables, etc.)
const amount = payable.amount.amount / Math.pow(10, payable.amount.precision)
```

## Response structure

```json
{
  "id": "lfyzcn76rvd200",
  "type": "subscription",          // single_purchase | subscription | physical | multi_use
  "status": "ACT",
  "lastFourDigits": "7071",        // last 4 digits of the PAN — the full PAN is never returned
  "expiryDate": "2030-04-30T23:59:59.000Z",
  "ownerId": "lywtbkp615b21t",     // userId of the owner
  "currency": "EUR",
  "availableBalance": { "amount": 91.38, "currency": "EUR", "precision": 2 },
  "spendingLimit": null            // null on subscription cards
}
```

## Pitfall — spendingLimit null on subscription cards

`spendingLimit` is `null` for `subscription` cards (confirmed S29 and S16). The available balance is read via `availableBalance` only. For `single_purchase` and `multi_use` cards, `spendingLimit` contains the cap.

## Resolving ownerId → employee name

`list_cards` returns `ownerId` (userId) but not the name. To display the name:

```json
// get_users with filter by ID
{
  "companyId": "<COMPANY_ID>",
  "ids": ["lywtbkp615b21t", "other_user_id"]
}
```

→ Returns `{ firstName, lastName, email }` for each userId. Build a userId → name map to enrich the cards.

## Available filters

| Parameter | Type | Description |
|-----------|------|-------------|
| `status` | string | A single status (PRE/ACT/BLO/REA/EXP/CAN/LOS/STO/DAM/CMD/CBL) |
| `type` | enum | single_purchase / subscription / physical / multi_use |
| `userId` | string | Filter by owner |
| `createdAfter` | YYYY-MM-DD | Cards created after this date |
| `createdBefore` | YYYY-MM-DD | Cards created before this date |

## Example user prompts

- "Which virtual cards are currently active and what is their available balance?"
- "Are there any cards with an unused residual balance?"
- "Show me the active cards for the Marketing team"