feat: export cog_basket_resolution() and cog_basket_unresolved()

Sidecar accessors for basket-mode results. cog_basket_resolution()
returns the full resolution tibble (drops candidates list-col by
default for readable printing). cog_basket_unresolved() filters to
ambiguous/no_match rows for iterative refinement.

man/cog_basket_unresolved.Rd

@@ -0,0 +1,20 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/basket.R
+\name{cog_basket_unresolved}
+\alias{cog_basket_unresolved}
+\title{Filter a basket resolution to unresolved rows}
+\usage{
+cog_basket_unresolved(x)
+}
+\arguments{
+\item{x}{A tibble returned by basket-mode [cog_gov_search()].}
+}
+\value{
+A tibble (subset of [cog_basket_resolution()]).
+}
+\description{
+Convenience wrapper that returns just the rows where `status` is
+`"ambiguous"` or `"no_match"` — the ones the user likely wants to
+refine before piping into a query verb. The `candidates` list-column
+is preserved so the user can drill into ambiguous match sets.
+}