Convert do.call calls to ParmOff

[Copilot]

Replaces all do.call calls across the package with ParmOff::ParmOff, and improves argument routing in magtri so that ... is forwarded to magaxis, magcon, and points instead of only magcon.

Changes

Package infrastructure

• Added ParmOff to Imports in DESCRIPTION with a Remotes: asgr/ParmOff entry
• Added importFrom("ParmOff", "ParmOff") to NAMESPACE
• Added testthat (>= 3.0.0), knitr, and rmarkdown to Suggests
• Added VignetteBuilder: knitr and Config/testthat/edition: 3

1-to-1 do.call → ParmOff replacements (no behaviour change)

• magaxis.R — axis (×6) and mtext (×2) calls
• magplot.R — maghist, magmap, points, magbar calls
• magbin.R — magmap (×3), magplot (×2), magbar calls
• magimage.R — image call
• magimageRGB.R — image call

magtri.R — the main improvement

Previously, all ... passed to magtri() were forwarded exclusively to magcon. Now a dots = list(...) is collected once and routed via ParmOff to every sub-function call:

Call	Before	After
magaxis(…) (all panels)	fixed args only	fixed args + user ...
magcon(…)	fixed args + all ...	fixed args + user ... (ParmOff deduplicates)
points(…)	fixed args only	fixed args + user ...

This means callers can now do things like:

magtri(chains, cex.axis = 0.7, lty = c(1, 1, 1), pch = 16)
#  cex.axis goes to every magaxis call (axis tick labels)
#  lty      overrides the default contour line types in magcon
#  pch      overrides the marker style in points

ParmOff's argument merging ensures user-supplied values override the defaults while avoiding duplicate-argument errors that the old do.call(func, c(list(fixed), dots)) pattern would throw.

Tests and vignette

• Added tests/testthat/test-parmoff-routing.R with 15 unit tests covering ParmOff argument routing through magaxis, magplot, magmap, magbin/plot.magbin, magimage, and magtri (including forwarding cex.axis → magaxis, lty → magcon, pch → points).
• Added vignettes/magicaxis.Rmd, a long-form vignette with fig.width = 6 / fig.height = 6 throughout, covering magaxis, magplot, maghist, magcon, magbin, magimage, and magtri; includes a dedicated section demonstrating the new ParmOff-based argument routing in magtri.

[asgr]

Add relevant unit tests and create a long form vignette magicaxis.Rmd that uses fig.width and fig.height of 6.

[Copilot]

Add relevant unit tests and create a long form vignette magicaxis.Rmd that uses fig.width and fig.height of 6.

Done in 523981a. Added:

• tests/testthat/test-parmoff-routing.R — 15 unit tests covering ParmOff argument routing through magaxis (forwarding cex.axis/col.axis, filtering unknown args, xlab/ylab via mtext), magplot (basic, log, z-coloured, histogram dispatch), magmap, magbin/plot.magbin, magimage, and magtri (return structure, forwarding cex.axis to magaxis, lty to magcon, pch to points, refvals, custom lab).

• vignettes/magicaxis.Rmd — long-form vignette with fig.width = 6 / fig.height = 6 throughout, covering magaxis, magplot, maghist, magcon, magbin, magimage, and magtri; includes a dedicated section on the new ParmOff-based argument routing in magtri.

Also updated DESCRIPTION with testthat, knitr, rmarkdown in Suggests, VignetteBuilder: knitr, and Config/testthat/edition: 3.