Add drop_input argument to create_model()

[roninsightrx]

Summary

• Adds a drop_input argument to create_model() that accepts a character vector of column names to mark as DROP in the NONMEM $INPUT record
• Validates that data is supplied and that all specified columns exist in the dataset
• Implements via string manipulation of $INPUT (same pattern as set_dv())

Test plan

• Test with drop_input = c("COL1", "COL2") and verify $INPUT contains DROP in place of those columns
• Test that an error is thrown when drop_input is used without data
• Test that an error is thrown when a non-existent column name is specified
• Verify existing create_model() behavior is unchanged when drop_input = NULL

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds support in create_model() for dropping specific dataset columns from the NONMEM $INPUT record by marking them as DROP, with corresponding documentation updates.

Changes:

• Added drop_input argument to create_model() and implemented $INPUT rewriting via new drop_input_columns() helper.
• Regenerated/added roxygen2 docs (man/create_model.Rd, new man/drop_input_columns.Rd) and updated create_regimen Rd usage ordering.
• Bumped package version in DESCRIPTION.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
R/create_model.R	Adds drop_input argument, validates inputs, and introduces $INPUT rewriting helper.
man/drop_input_columns.Rd	New roxygen2-generated documentation for drop_input_columns().
man/create_regimen.Rd	Roxygen2 regeneration adjusts argument ordering in usage/arguments.
man/create_model.Rd	Roxygen2 regeneration adds drop_input to docs.
DESCRIPTION	Version bump.

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[Copilot]

drop_input_columns() rebuilds the model via create_model_from_file(tmpmod, data = model$dataset), but create_model_from_file() re-reads the model with read_model_from_string() and drops the loaded dataset. This means using drop_input will likely return a model with mod$dataset == NULL and can break subsequent logic in create_model() (e.g., BLQ checks immediately after this block rely on names(mod$dataset)). Re-attach the original dataset to the returned model (e.g., capture data <- model$dataset and call pharmr::set_dataset(new_model, path_or_df = data, datatype = 'nonmem') after re-reading, or avoid create_model_from_file() and use read_model_from_string() + explicit set_dataset() like other helpers do).

Suggested change

	create_model_from_file(tmpmod, data = model$dataset)
	data <- model$dataset
	new_model <- create_model_from_file(tmpmod, data = data)
	if (!is.null(data)) {
	new_model <- pharmr::set_dataset(new_model, path_or_df = data, datatype = "nonmem")
	}
	new_model