test: add JSON/YAML fixtures to every preset dir

Each preset's test-files/ subdir previously only had JS/TS files, so
the existing CI step didn't exercise the json + yaml configs included
by every environment preset. That let the nextjs/preact missing
files-scope bug slip through CI.

Also align the AGENTS.md Node matrix note with the actual CI matrix
(20, 22, 24).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JoshTheWanderer

AGENTS.md

@@ -132,7 +132,7 @@ Note: `HUSKY=0` environment variable disables hooks in CI.
 
 ### CI Pipeline (`.github/workflows/ci.yml`)
 - Runs on pull requests
-- Tests against Node.js 18, 20, 22
+- Tests against Node.js 20, 22, 24 (matches `engines` field)
 - Lints source code with `npx eslint src`
 - Validates config against `test-files/` (expects violations to prove rules work)
 

test-files/angular/test.json

@@ -0,0 +1,8 @@
+{
+  "name": "test",
+  "version": "1.0.0",
+  "description": "Test JSON file",
+  "scripts": {
+    "test": "echo test"
+  }
+}

test-files/angular/test.yml

@@ -0,0 +1,7 @@
+name: test-config
+version: 1.0.0
+# Fixed indentation
+description: Test YAML file
+scripts:
+  test: echo test
+  build: echo build

test-files/nestjs/test.json

@@ -0,0 +1,8 @@
+{
+  "name": "test",
+  "version": "1.0.0",
+  "description": "Test JSON file",
+  "scripts": {
+    "test": "echo test"
+  }
+}

test-files/nestjs/test.yml

@@ -0,0 +1,7 @@
+name: test-config
+version: 1.0.0
+# Fixed indentation
+description: Test YAML file
+scripts:
+  test: echo test
+  build: echo build

test-files/nextjs/test.json

@@ -0,0 +1,8 @@
+{
+  "name": "test",
+  "version": "1.0.0",
+  "description": "Test JSON file",
+  "scripts": {
+    "test": "echo test"
+  }
+}

test-files/nextjs/test.yml

@@ -0,0 +1,7 @@
+name: test-config
+version: 1.0.0
+# Fixed indentation
+description: Test YAML file
+scripts:
+  test: echo test
+  build: echo build

test-files/nodejs/test.json

@@ -0,0 +1,8 @@
+{
+  "name": "test",
+  "version": "1.0.0",
+  "description": "Test JSON file",
+  "scripts": {
+    "test": "echo test"
+  }
+}

test-files/nodejs/test.yml

@@ -0,0 +1,7 @@
+name: test-config
+version: 1.0.0
+# Fixed indentation
+description: Test YAML file
+scripts:
+  test: echo test
+  build: echo build

test-files/preact/test.json

@@ -0,0 +1,8 @@
+{
+  "name": "test",
+  "version": "1.0.0",
+  "description": "Test JSON file",
+  "scripts": {
+    "test": "echo test"
+  }
+}