fastfocal 0.1.3

This release represents the version used to generate all benchmark results and figures reported in the forthcoming manuscript.

Performance optimizations.
Refined core routines for faster runtime in typical benchmark scenarios.
Vignettes: explicit graphics-state resets per CRAN guidance:
- Save and restore par() with oldpar <- par(no.readonly = TRUE); par(oldpar) around changes.
- Reset layout() with layout(1) when used.

If using fastfocal in academic work, cite this version as:

Wan, H.Y. (2025). fastfocal v0.1.3. GitHub. https://github.com/yourrepo/fastfocal/releases/tag/v0.1.3

fastfocal 0.1.2

Fix: NA-semantic parity with terra::focal() under na.rm=TRUE/FALSE and na.policy="omit"; removed speckle artifacts at NA boundaries.
Fix: Correct matrix orientation and final transpose in FFT path.
Perf: Auto-padding to next 5-smooth lengths (2*3*5 factors) to avoid large-prime slowdowns in FFTs.
Rebuilt vignettes and refreshed documentation.
Fixed Rd markup (e.g., replaced {terra} with \pkg{terra}).
Removed non-ASCII characters from R sources and roxygen; math now uses Rd math (e.g., \eqn{\sigma}).
Vignettes now restore user graphics state:
- Added oldpar <- par(no.readonly = TRUE); on.exit(par(oldpar), add = TRUE) in chunks that modify par(...).
- Added on.exit(layout(1), add = TRUE) in chunks that use layout(...).
No changes to options() or working directory in examples/vignettes.

First public release (submitted to CRAN).
Added Zenodo DOI and updated citation information.
Updated vignettes (index.Rmd and benchmark.Rmd) with correct version numbers and DOI.
Clarified that the FFT backend supports only sum and mean; other statistics handled by the terra backend.
README and DESCRIPTION updated for consistency (license MIT, DOI, installation instructions).
Added inst/CITATION file so that citation("fastfocal") prints the DOI and pkgdown URL.