Remove re-exports of term's defunct parameters functions and ignore .claude

[joethorley]

term::parameters() and term::`parameters<-`() become defunct in term 0.4.0 (poissonconsulting/term#103). mcmcr re-exports both, so as of that release mcmcr exports two functions that can only error.

• Delete R/parameters.R, dropping parameters() and parameters<-() from mcmcr's exports and from the term importFrom block
• Regenerate NAMESPACE and man/reexports.Rd
• Add ^\.claude$ to .Rbuildignore, clearing the "checking for hidden files and directories" NOTE (term already carries this entry)

The tests that exercised the re-exports were already removed in #83, so nothing else changes.

Breaking change: mcmcr::parameters() and mcmcr::parameters<-() are no longer exported. Use pars() and pars<-(). This warrants the 0.7.0 bump that coef(directional_information =) is already targeting.

Verification

Checked against the term 0.4.0 development version (0.3.7.9019) installed into a scratch library:

• devtools::test() on mcmcr main before this change: all tests pass, so this is cleanup rather than a fix for a broken revdep
• devtools::check() with these changes: Status: OK
• pkgbuild::build() confirms .claude no longer appears in the tarball
• No reverse dependency calls mcmcr::parameters(): checked mcmcderive, nlist, mbr, embr, smbr2 and jmbr; every hit is a local variable or a package's own subset(parameters =) argument

CI on this branch is red for a reason that predates it: tidy.mcmcr() forwards directional_information to nlist::tidy.mcmc.list(), which only accepts it in the unreleased nlist 0.5.0. See the comment below.

🤖 Generated with Claude Code

[joethorley]

CI on this branch is red, but the failure is pre-existing on main and unrelated to this change.

── Error ('test-tidy.R:3:3'): tidy.mcmcr ──
Error in `tidy.mcmc.list(as_mcmc_list(x), simplify = simplify,
  directional_information = directional_information)`: `...` must be unused.

tidy.mcmcr() gained a directional_information argument in #84 and forwards it to nlist::tidy.mcmc.list(), which only accepts it in the unreleased nlist 0.5.0. CI installs nlist 0.4.0 from CRAN, so the argument lands in ... and trips chk_unused().

The identical failure appears in the last five R-CMD-check runs on main (run 29480784999 onward, since 2026-07-15), predating this branch. Unblocking it needs nlist 0.5.0 on CRAN, not a change here.

Local devtools::check() with the dev nlist 0.4.0.9006 installed: Status: 1 NOTE (the .claude hidden-directory note).