CSVFormatter returns "no tables defined" for top-level map[string]any

[adityathebe]

After fixing #38, formatting a top-level map[string]any as CSV now succeeds at the conversion stage but the formatter errors out with no tables defined.

Repro:

data := map[string]any{"name": "clicky", "count": 42}
out, err := csvFormatter.Format(data, FormatOptions{Format: "csv"})
// out == "", err == "no tables defined"

The Markdown path renders the map as a key/value list, but CSVFormatter.FormatPrettyData (formatters/csv_formatter.go) only handles *api.TextTable and returns the error when FirstTable() is nil. Maps produce a TypedMap, not a Table, so the formatter has no way to render them as CSV today.