Add MARIMO_FOLDER to deptry configuration variables

[tschm]

Conditionally append MARIMO_FOLDER to DEPTRY_FOLDERS and add --ignore DEP004 to DEPTRY_IGNORE when the directory exists.

[Copilot]

Pull request overview

This PR refactors the deptry dependency checking functionality from a monolithic target in .rhiza/rhiza.mk into a modular architecture split across multiple files. The refactoring enables conditional inclusion of both SOURCE_FOLDER and MARIMO_FOLDER in deptry checks, with appropriate flags applied automatically based on which directories exist.

Changes:

• Extracts deptry target from rhiza.mk into a new modular file src.mk
• Adds conditional MARIMO_FOLDER support to deptry configuration via 03-marimo.mk
• Updates test suite to recognize the new src.mk file

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
.rhiza/rhiza.mk	Removes the old monolithic deptry target definition (lines 233-245)
.rhiza/make.d/src.mk	New file defining the deptry target with conditional SOURCE_FOLDER inclusion and variable-based folder configuration
.rhiza/make.d/03-marimo.mk	Adds conditional logic to append MARIMO_FOLDER to DEPTRY_FOLDERS and add --ignore DEP004 flag when the directory exists
tests/test_rhiza/test_makefile.py	Updates SPLIT_MAKEFILES list to include the new src.mk file

[Copilot]

Consider initializing DEPTRY_FOLDERS and DEPTRY_IGNORE variables at the top of this file before appending to them, for clarity and consistency with Make best practices. While using += on undefined variables works in Make (treating them as initially empty), explicit initialization makes the code more maintainable and self-documenting.

For example, add at the top:
DEPTRY_FOLDERS ?=
DEPTRY_IGNORE ?=

This is especially important since this file defines the deptry target and should be the authoritative source for these variables.

[Copilot]

For consistency with other .mk files in this directory (e.g., 01-test.mk, 03-marimo.mk), consider adding a .PHONY declaration for the deptry target at the top of this file after the variable definitions:

.PHONY: deptry

While the target is already declared as PHONY in the main rhiza.mk file, having it declared locally makes the file more self-contained and follows the pattern established in other make.d files.

[Copilot]

Consider renaming this file to follow the numeric prefix convention documented in .rhiza/make.d/README.md. Since this file defines a target (deptry) which is a quality checking tool, it could be numbered in the 20-79 range (e.g., "02-src.mk" or similar) for consistency with other target-defining files like 01-test.mk, 03-marimo.mk, etc.

However, if the intent is for this file to represent core/fundamental source folder configuration (without a prefix to indicate its foundational nature), then the current naming is acceptable.

[Copilot]

The INFO output on lines 11-13 is more verbose than the pattern used in other targets (see 01-test.mk, 02-book.mk, etc.), which typically just print a brief description like "Running deptry..." rather than showing variable values and the full command.

Consider simplifying to match the existing pattern:
@printf "${BLUE}[INFO] Running deptry on ${DEPTRY_FOLDERS}...${RESET}\n"

However, the current verbose output could be valuable for debugging during the initial rollout of this refactored functionality, so this is a minor style preference rather than a requirement.