Qualify all {.help} tags with AMR:: and convert backtick ?func references

- Add AMR:: namespace prefix and trailing () to all {.help} cli markup
  so they render as clickable help links (e.g. {.help AMR::as.sir}())
- Convert `?funcname` backtick-quoted help references to {.help AMR::funcname}()
  in aa_helper_functions.R, custom_eucast_rules.R, interpretive_rules.R,
  key_antimicrobials.R, mo.R, plotting.R, resistance_predict.R, and sir.R
- Skipped `?proportion` in sir_calc.R as 'proportion' is not exported

https://claude.ai/code/session_01XHWLohiSTdZvCutwD7ag2b

R/plotting.R

@@ -412,7 +412,7 @@ create_scale_sir <- function(aesthetics, colours_SIR, language, eucast_I, ...) {
 
   scale$labels <- function(x) {
     stop_ifnot(all(x %in% c(levels(NA_sir_), "SI", "IR", NA)),
-      "Apply `scale_", aesthetics[1], "_sir()` to a variable of class 'sir', see `?as.sir`.",
+      "Apply `scale_", aesthetics[1], "_sir()` to a variable of class 'sir', see {.help AMR::as.sir}().",
       call = FALSE
     )
     x <- as.character(x)