refactor: improve Monaco language definitions

CLAUDE.md

@@ -165,8 +165,9 @@ src/
 ## Testing Conventions
 
 - Unit tests in `src/util/__tests__/*.spec.ts` with Vitest + jsdom
+- Monarch tokenizer tests co-located in `src/monaco/language/__tests__/` — use shared `tokenize-helper.ts` (`registerLanguage`, `tokenizeLines`, `tokenBuilder`)
 - Global test functions (`describe`, `it`, `expect`) — `globals: true` in vitest config
-- Setup file: `tests/unit/setup.ts`
+- Setup file: `tests/unit/setup.ts` — includes `CSS.escape` and `window.matchMedia` polyfills required by Monaco in jsdom
 - Time manipulation utility: `timeTravel(date, callback)` in `tests/unit/utils.ts`
 - Parameterized tests: `it.each([...])` pattern
 - Test store actions/mutations independently from UI

docs/docs/features/file-editor.md

@@ -21,9 +21,9 @@ Syntax highlighting is provided for the following file types:
 
 | File Type                                                 | Highlighted Elements                                                                                                                     |
 |-----------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------|
-| **Klipper config** (`.cfg`)                               | Section headers, key names, values, boolean constants, comments, and SAVE_CONFIG block markers                                           |
-| **Moonraker config** (`.conf`)                            | Section headers, key names, values, boolean constants, space-prefixed escaped comment sigils (`\#`, `\;`), inline comments, and comments |
-| **G-code** (`.gcode`, `.g`, `.gc`, `.gco`, `.ufp`, `.nc`) | G/M/T commands, coordinates, feed rates, tool and offset registers, math functions, macro variables, and control keywords                |
+| **Klipper config** (`.cfg`)                               | Section headers, key names, values, comments, and SAVE_CONFIG block markers                                                              |
+| **Moonraker config** (`.conf`)                            | Section headers, key names, values, and comments                                                                                         |
+| **G-code** (`.gcode`, `.g`, `.gc`, `.gco`, `.ufp`, `.nc`) | G/M/T/N command codes, checksum tags, M117/M118 messages, macro names and parameters, parameter letters (X, Y, Z, E, F, S), and comments  |
 | **Log files** (`.log`)                                    | Log-level colorization (debug, info, warning, error, critical), timestamps, URLs, UUIDs, git SHAs, exception names, and stack traces     |
 | **JSON**                                                  | Full validation and IntelliSense via a dedicated language worker                                                                         |
 | **CSS, SCSS, Less**                                       | Property completion, hover, and validation via a dedicated language worker                                                               |