BUG in Gamma API `/events`'s closed param which default to `true` while doc says `false` (propagates to CLI)

[souhailaS]

The Gamma docs for GET /events say closed defaults to false, but the API actually defaults to closed=true (returns only settled events when the param is omitted).

What the docs say --> https://docs.polymarket.com/developers/gamma-markets-api/get-events

Quick test of the problem:

curl -s "https://gamma-api.polymarket.com/events?series_id=10345&limit=100" \
    | jq '[.[] | .closed] | group_by(.) | map({(.[0]|tostring): length}) | add'

Should return {"true": 0} but will show {"true": 100} as it defaults to closed == true when no param is set.

This reflects on the CLI too. Running polymarket-cli events list --tag nba with no flags returns only closed/settled events instead of active ones, because the CLI omits the closed query param when no --closed/--active flag is passed.

The --help does not document the defaults

[osr21]

Confirmed + reproducible + fix

Reproduced the behaviour. The Gamma API `GET /events` returns **only closed markets** when the `closed` param is omitted, which is the opposite of what the docs state (`closed=false` default). This propagates into the CLI wherever `closed` isn't explicitly set.

```bash
# Confirm — returns all closed, no open:
curl -s "https://gamma-api.polymarket.com/events?limit=5" | jq '[.[].closed]'
# → [true, true, true, true, true]

# Correct — must explicitly opt in to open markets:
curl -s "https://gamma-api.polymarket.com/events?limit=5&closed=false" | jq '[.[].closed]'
# → [false, false, false, false, false]
```

### Fix in the CLI

In whatever module builds the Gamma query (typically `gamma.ts` / `gamma.py`), always include `closed` explicitly instead of omitting it:

```ts
// Before (omission causes server default of closed=true):
const params = new URLSearchParams({ limit: String(limit) });

// After — always send the flag; let the user override:
const params = new URLSearchParams({
limit: String(limit),
closed: String(options.closed ?? false),  // explicit default=false matches docs
});
```

```python
# Python equivalent
params = {
  "limit": limit,
  "closed": str(options.get("closed", False)).lower(),  # "false" by default
}
```

### Impact

Any CLI command that lists, searches, or filters markets without explicitly passing `--closed` silently operates on the settled-only dataset. Users seeing "no results" or stale markets are almost certainly hitting this.

### Related

The same bug exists in `GET /markets` with the `closed` param — worth fixing both in the same PR.