Modernise messaging infrastructure with cli support

Rewrites message_(), warning_(), stop_() to use cli::cli_inform(),
cli::cli_warn(), and cli::cli_abort() when the cli package is available,
with a fully functional plain-text fallback for environments without cli.

Key changes:
- New cli_to_plain() helper converts cli inline markup ({.fun}, {.arg},
  {.val}, {.field}, {.cls}, {.pkg}, {.href}, {.url}, etc.) to readable
  plain-text equivalents for the non-cli fallback path
- word_wrap() simplified: drops add_fn, ANSI re-index algorithm, RStudio
  link injection, and operator spacing hack; returns pasted input unchanged
  when cli is available
- stop_() no longer references AMR_env$cli_abort; uses pkg_is_available()
  directly; passes sys.call() objects to cli::cli_abort() call= argument
- Removed add_fn parameter from message_(), warning_(), and word_wrap()
- All call sites across R/ updated: add_fn arguments removed, some paste0-
  based string construction converted to cli glue syntax ({.fun as.mo},
  {.arg col_mo}, {n} results, etc.)
- cli already listed in Suggests; no DESCRIPTION dependency changes needed

https://claude.ai/code/session_01XHWLohiSTdZvCutwD7ag2b

R/custom_mdro_guideline.R

@@ -145,15 +145,15 @@ custom_mdro_guideline <- function(..., as_factor = TRUE) {
   )
   stop_if(
     identical(dots, "error"),
-    "rules must be a valid formula inputs (e.g., using '~'), see `?mdro`"
+    "rules must be a valid formula inputs (e.g., using '~'), see {.fun mdro}"
   )
   n_dots <- length(dots)
-  stop_if(n_dots == 0, "no custom rules were set. Please read the documentation using `?mdro`.")
+  stop_if(n_dots == 0, "no custom rules were set. Please read the documentation using {.fun mdro}.")
   out <- vector("list", n_dots)
   for (i in seq_len(n_dots)) {
     stop_ifnot(
       inherits(dots[[i]], "formula"),
-      "rule ", i, " must be a valid formula input (e.g., using '~'), see `?mdro`"
+      "rule ", i, " must be a valid formula input (e.g., using '~'), see {.fun mdro}"
     )
 
     # Query
@@ -202,7 +202,7 @@ c.custom_mdro_guideline <- function(x, ..., as_factor = NULL) {
   }
   for (g in list(...)) {
     stop_ifnot(inherits(g, "custom_mdro_guideline"),
-      "for combining custom MDRO guidelines, all rules must be created with `custom_mdro_guideline()`",
+      "for combining custom MDRO guidelines, all rules must be created with {.fun custom_mdro_guideline}",
       call = FALSE
     )
     vals <- attributes(x)$values
@@ -259,16 +259,15 @@ run_custom_mdro_guideline <- function(df, guideline, info) {
       }
     )
     if (identical(qry, "error")) {
-      warning_("in `custom_mdro_guideline()`: rule ", i,
+      warning_("in {.fun custom_mdro_guideline}: rule ", i,
         " (`", as.character(guideline[[i]]$query), "`) was ignored because of this error message: ",
         AMR_env$err_msg,
-        call = FALSE,
-        add_fn = font_red
+        call = FALSE
       )
       next
     }
-    stop_ifnot(is.logical(qry), "in custom_mdro_guideline(): rule ", i, " (`", guideline[[i]]$query,
-      "`) must return `TRUE` or `FALSE`, not ",
+    stop_ifnot(is.logical(qry), "in {.fun custom_mdro_guideline}: rule ", i, " (`", guideline[[i]]$query,
+      "`) must return {.code TRUE} or {.code FALSE}, not ",
       format_class(class(qry), plural = FALSE),
       call = FALSE
     )