chore(desc): R version floor, ByteCompile, Suggests

[davidbudzynski]

Problem
DESCRIPTION:13 says Depends: R (>= 3.1.0), which is not accurate: ...length() needs R >= 3.2, and R_RegisterCCallable / STRING_PTR_RO need newer R. ByteCompile: TRUE should be yes per WRE. Suggests: knitr, rmarkdown is missing packages used in docs/tests. Repository: CRAN should not be in the dev DESCRIPTION.

Acceptance

• Bump to R (>= 3.5.0) (matches the kit.h:19-22 fallback) or >= 4.0 if the isDataFrame shim is dropped
• ByteCompile: yes, add Config/testthat/edition, Config/Needs/website, RoxygenNote if adopted
• R CMD check --as-cran clean on devel

[davidbudzynski]

Review for #58 (verified on master @ 4d1d79d, R 4.6.1):

R floor 3.1.0 is wrong — 3.5.0 is the minimal safe bump:

• R/call.R uses ...length() in 13 wrappers (pall/pany/pcount*/fpmin/fpmax/prange/psum etc.) — needs > 3.1.
• src/init.c:39-66 calls R_RegisterCCallable x28 — needs newer R than 3.1.
• STRING_PTR_RO used across src/share.c, vswitch.c, dup.c, utils.c, psum.c with no fallback — fails on old R.
• src/kit.h:19-22 already shims DATAPTR_RO for R < 3.5.0, so bumping to R (>= 3.5.0) lets that fallback stay as-is and is consistent. No code change needed.
• src/kit.h:29-31 shims isDataFrame -> Rf_isFrame for R < 4.5.0 (on >= 4.5 R headers provide isDataFrame -> Rf_isDataFrame). Keep the shim with a 3.5 floor. Note: acceptance says '>= 4.0 if shim dropped' — strictly it is >= 4.5 to drop, and that would break the current CI matrix (oldrel-4 ≈ 4.2). So 3.5.0 is the right choice; leave a 4.5 bump for later with a CI trim.

Other fields:

• ByteCompile: TRUE -> yes per WRE. Done.
• Repository: CRAN removed from dev tree (added back by CRAN on release). Done.
• Suggests: already correct after 966330b + 089cb7e — data.table/tibble used conditionally in inst/tinytest/test-enc.R:52,61, tinytest in tests/tinytest.R, knitr/rmarkdown in vignettes/introduction.Rmd. rg shows no other ::/library() needs. Keep as data.table, knitr, rmarkdown, tibble, tinytest.
• Config/Needs/website: pkgdown added (pkgdown site in _pkgdown.yml + .github/workflows/pkgdown.yaml). Config/testthat/edition intentionally NOT added (migrated to tinytest, removed in 089cb7e). RoxygenNote NOT added (man/*.Rd are hand-written, no roxygen).
• CI matrix (oldrel-1..4 + release + devel) all satisfy >= 3.5, no workflow change needed.

Check:

• R CMD build: DESCRIPTION meta-information OK.
• R CMD check --as-cran --no-manual --no-build-vignettes: DESCRIPTION OK, dependencies OK, tests (tinytest.R) OK, no metadata NOTEs. Remaining 3 WARNINGs + 1 NOTE are env-only (missing pandoc/checkbashisms, inst/doc absent due to --no-build-vignettes).

Branch chore/58-desc-metadata implements: Depends 3.5.0, ByteCompile yes, drop Repository, add Config/Needs/website + NEWS.md note. PR to follow against master.