fix: compare YAML against the maintained RedCMD grammar (not the dead bundle)

Correct the YAML baseline + its labeling. VS Code already switched YAML OFF the dead textmate/yaml.tmbundle to the maintained RedCMD/YAML-Syntax-Highlighter (microsoft/vscode#232244); VS Code's bundled YAML IS RedCMD (vendored), so scope-gap was already comparing against it — confirmed: RedCMD upstream gives the identical 89.7%/46.5%/-43.2.

- scope-gap-yaml.ts now DEFAULTS to RedCMD upstream (/tmp/redcmd-yaml; git clone --depth 1 https://github.com/RedCMD/YAML-Syntax-Highlighter). Its header had wrongly said 'VS Code's YAML grammar is the unmaintained textmate/yaml.tmbundle' — fixed.
- README: a note spells out which 'official' grammar each row compares against — HTML = dead textmate/html.tmbundle (the #203212 target), YAML = maintained RedCMD, JS/TS = Microsoft's TypeScript-TmLanguage. So YAML's -43 gap is Monogram vs a *maintained* grammar, not a dead bundle.

(RedCMD upstream's last commit is 2024-12-16 / tag 1.4.1 — far fresher than textmate's 6y, but ~18mo stale by 2026-06, so 'current upstream' is more precise than 'actively maintained'.)

Author: johnsoncodehk

README.md

@@ -24,6 +24,8 @@ Per-grammar alignment vs the **official parser** as the neutral oracle (`node te
 | YAML | 83.0% · 63.1% | 46.5% vs 89.7% |
 <!-- coverage:end -->
 
+<sub>**Which “official” grammar each row compares against:** HTML’s is the unmaintained [`textmate/html.tmbundle`](https://github.com/textmate/html.tmbundle) — the #203212 case Monogram targets. YAML’s is the maintained [RedCMD/YAML-Syntax-Highlighter](https://github.com/RedCMD/YAML-Syntax-Highlighter) that VS Code switched to ([microsoft/vscode#232244](https://github.com/microsoft/vscode/pull/232244)) — so YAML’s gap is Monogram vs a *maintained* grammar, not a dead bundle. JS/TS use Microsoft’s maintained [TypeScript-TmLanguage](https://github.com/microsoft/TypeScript-TmLanguage).</sub>
+
 ## Quick start
 
 Requires Node 24+ (runs `.ts` directly — no build step, no `tsx`).

test/scope-gap-yaml.ts

@@ -1,17 +1,21 @@
-// scope-gap-yaml.ts — YAML adapter for the unified scope-gap harness. vscode#203212 language #1:
-// VS Code's YAML grammar is the unmaintained textmate/yaml.tmbundle; the oracle is the `yaml`
-// package (maintained). Run (bare node): node test/scope-gap-yaml.ts
-//   Override the official grammar: MONOGRAM_OFFICIAL_YAML=/path/to/yaml.tmLanguage.json
+// scope-gap-yaml.ts — YAML adapter for the unified scope-gap harness. NOTE: unlike most of the
+// vscode#203212 list, VS Code already switched YAML OFF the dead textmate/yaml.tmbundle TO the
+// maintained RedCMD/YAML-Syntax-Highlighter (microsoft/vscode#232244). So YAML's "official"
+// baseline here is that MAINTAINED grammar — this gap is Monogram vs a maintained competitor, not
+// a dead bundle. Default = RedCMD UPSTREAM; clone it first:
+//   git clone --depth 1 https://github.com/RedCMD/YAML-Syntax-Highlighter /tmp/redcmd-yaml
+// (VS Code's bundled YAML is the same grammar — identical result; set MONOGRAM_OFFICIAL_YAML to
+//  .../extensions/yaml/syntaxes/yaml.tmLanguage.json for that.) Oracle = the `yaml` package.
+// Run (bare node): node test/scope-gap-yaml.ts
 import { readdirSync, readFileSync } from 'node:fs';
 import { dirname, join } from 'node:path';
 import { parse as yamlParse, parseAllDocuments } from 'yaml';
 import { run } from './scope-gap.ts';
 import { yamlOracle } from './yaml-oracle.ts';
 
-const OFFICIAL = process.env.MONOGRAM_OFFICIAL_YAML
-  ?? '/Applications/Visual Studio Code.app/Contents/Resources/app/extensions/yaml/syntaxes/yaml.tmLanguage.json';
-// VS Code's YAML grammar is a dispatcher stub that include()s version-specific sub-grammars in
-// the same syntaxes/ dir — load them all, or the official scopes nothing (everything → root).
+const OFFICIAL = process.env.MONOGRAM_OFFICIAL_YAML ?? '/tmp/redcmd-yaml/syntaxes/yaml.tmLanguage.json';
+// The RedCMD/VS Code YAML grammar is a dispatcher stub that include()s version-specific
+// sub-grammars in the same syntaxes/ dir — load them all, or the official scopes nothing.
 const SYN = dirname(OFFICIAL);
 const officialExtra: Record<string, string> = {
   'source.yaml.1.2': join(SYN, 'yaml-1.2.tmLanguage.json'),