Replace single-quoted literals in messaging calls with cli markup

Converted bare 'value' strings inside stop_(), warning_(), message_()
to appropriate cli markup:
- {.val}: option values ('drug', 'dose', 'administration', 'SDD', 'logbook')
- {.cls}: class names ('sir', 'mo')
- {.field}: column names ('mo' in mo_source)
- {.code}: object/dataset names ('clinical_breakpoints')

Files changed: ab_from_text.R, av_from_text.R, sir.R, sir_calc.R, mo_source.R

https://claude.ai/code/session_01XHWLohiSTdZvCutwD7ag2b

NEWS.md

@@ -48,6 +48,7 @@
 * New internal `cli_to_plain()` converts `cli` markup to plain text for non-cli path
 * All internal call sites updated to `cli` glue syntax
 * CI dev-version and old-tinytest workflows now only run on `main` branch pushes
+* Single-quoted literal values in messaging calls replaced with `{.val}`, `{.cls}`, `{.field}`, or `{.code}` markup throughout
 
 
 # AMR 3.0.1