test: raise covr coverage toward 90% target

[bbuchsbaum]

Summary

Raises meaningful R package test coverage for the portfolio coverage-target gate (issue #5).

Metric	Value
Starting coverage (issue / default-branch evidence)	80.00%
Final hosted test-coverage (this PR)	93.12%
Target	≥ 90.00%

Adds focused tests for previously thin public paths: DataLad install/get/update success and CLI failure, tf_prefetch, tf_copy_to_dest, NIfTI/GIFTI reader dispatch, config/env boundaries, skeleton remote/MD5 paths, describe print edges, and CLI wipe/help branches.

Motivation

Issue #5 reports measured line coverage at 80% against a 90% portfolio target. This PR only adds meaningful tests; it does not weaken expectations, skip broadly, or add unjustified # nocov annotations.

Cache / data implications

None. Tests continue to use tempdir caches and the bundled skeleton (templateflow.test.forcebundled), with network mocked where downloads would otherwise be required.

Checks run

• Hosted test-coverage → 93.12% (pass)
• R-CMD-check (ubuntu release/devel/oldrel, macos release) → pass
• pkgdown → pass
• Local full testthat suite → 0 failures / 0 errors
• Pre-existing blocker (also red on main): legacy workflow .github/workflows/r.yml job build (3.6.3) fails at setup-r with HTTP 404 for R 3.6.3 (unavailable on current macOS runners). That matrix version is also below package Depends: R (>= 4.1.0). Not changed here to keep the PR scoped to the coverage gate; modern R-CMD-check already covers supported R versions.

Issue #5 left open until the portfolio monitor verifies the merged default-branch SHA and hosted evidence.

  

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.11%. Comparing base (7ef644f) to head (e0b2a42).

Additional details and impacted files

@@             Coverage Diff             @@
##             main       #6       +/-   ##
===========================================
+ Coverage   80.00%   93.11%   +13.11%     
===========================================
  Files          12       12               
  Lines        1090     1090               
===========================================
+ Hits          872     1015      +143     
+ Misses        218       75      -143     

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[cursor]

Approved. Cursor Security Agent completed successfully with no findings requiring human review; Cursor Bugbot was not running on this PR. No reviewers were assigned.

  

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