Reshapes a `scan_untested_envs()` result into one row per genotype x planting date, carrying the credible bounds and the envelope position. Useful on its own when you want the numbers rather than a plot.
Arguments
- scan
a `scan_untested_envs` object whose new "environments" are candidate planting dates.
- dates
either (a) a data.frame with a column `env` matching the scan's new-environment names and a column giving the date, or (b) a vector of dates in the same order as the scan's new environments.
- date_col
name of the date column when `dates` is a data.frame.
- genotypes
optional character vector to subset genotypes.
- group
optional named vector or data.frame (`gid`, `group`) assigning genotypes to groups, for group-mean curves.
