Fix R-devel CI: pin roxygen2 7.2.3 on all platforms, add layered tryCatch fallbacks

[Copilot]

roxygen2 ≥ 7.3.0 has a parser_setMethod bug — it calls methods::getMethod() with no error handling, which crashes in clean Rscript sessions when S4 method tables for primitives ([[, [, $) are unpopulated. R-devel was exempt from the 7.2.3 pin, so it used 7.3.x and failed every run with no method found for function '[[' and signature hyperSpec.

A secondary issue: the tryCatch fallback called git checkout HEAD -- NAMESPACE man/, but both are gitignored and untracked — always failing with pathspec did not match any file(s) known to git, leaving no NAMESPACE for R CMD check.

Changes

• R-CMD-check.yaml
  • Remove if: matrix.config.r != 'devel' from "Install roxygen2 7.2.3" — pins 7.2.3 on all platforms including R-devel
  • Replace the single-step git restore in the tryCatch error handler with two ordered fallbacks:
    1. git restore — succeeds if NAMESPACE/man/ are ever pre-committed (Bioconductor/Matrix pattern)
    2. Source-compile roxygen2 7.2.3 against current R headers — handles future C-ABI breaks (e.g. SET_GROWABLE_BIT symbol removal in R 4.6.0-pre) where the RSPM binary fails but a freshly compiled .so succeeds
  • Update comments to reflect actual failure mode (parser_setMethod, not ABI break)

ok <- tryCatch({
  devtools::document()
  TRUE
}, error = function(e) {
  message("devtools::document() failed: ", conditionMessage(e))

  # Fallback 1: restore from git (works when docs are pre-committed)
  ret <- system2("git", c("checkout", "HEAD", "--", "NAMESPACE", "man/"),
                 stdout = TRUE, stderr = TRUE)
  if (file.exists("NAMESPACE")) { message("NAMESPACE restored from git."); return(FALSE) }

  # Fallback 2: compile from source against current R headers
  tryCatch({
    remotes::install_version("roxygen2", "7.2.3", type = "source", quiet = TRUE)
    devtools::document()
    TRUE
  }, error = function(e2) { ...; FALSE })
})