Replace bare backticks with cli inline markup across all messaging calls

- {.arg} for argument names in stop_/warning_/message_ calls
- {.cls} after "of class" text in format_class() and elsewhere
- {.fun} for function names (replaces `fn()` pattern)
- {.pkg} for tidyverse package names (dplyr, ggplot2)
- {.code} for code literals (TRUE, FALSE, expressions)
- Rewrite print.ab: use cli named-vector with * bullets and code
  highlighting when cli >= 3.0.0; keep plain-text fallback otherwise
- Fix typo in as.sir(): "of must be" -> "or must be"
- switch sir.R verbose notes from message() to message_()

https://claude.ai/code/session_01XHWLohiSTdZvCutwD7ag2b

R/disk.R

@@ -119,7 +119,7 @@ as.disk <- function(x, na.rm = FALSE) {
         sort() %pm>%
         vector_and(quotes = TRUE)
       cur_col <- get_current_column()
-      warning_("in `as.disk()`: ", na_after - na_before, " result",
+      warning_("in {.fun as.disk}: ", na_after - na_before, " result",
         ifelse(na_after - na_before > 1, "s", ""),
         ifelse(is.null(cur_col), "", paste0(" in column '", cur_col, "'")),
         " truncated (",