chore: add syntax check and reorder CI pipeline

Add cross-platform 'syntax' step using node --check for each source file.
Reorder CI: syntax → lint → format:check → test (fast checks first).

Author: euxx

DEVELOPMENT.md

@@ -19,20 +19,21 @@ Open the project in VS Code and press **F5** to launch the Extension Development
 
 ## Scripts
 
-| Command                | Description                           |
-| ---------------------- | ------------------------------------- |
-| `npm test`             | Run tests (Vitest)                    |
-| `npm run ci`           | Run all checks (test + lint + format) |
-| `npm run lint`         | Lint code (oxlint)                    |
-| `npm run format`       | Format code (oxfmt)                   |
-| `npm run format:check` | Check code formatting                 |
-| `npm run package`      | Package extension as `.vsix`          |
+| Command                | Description                                    |
+| ---------------------- | ---------------------------------------------- |
+| `npm test`             | Run tests (Vitest)                             |
+| `npm run ci`           | Run all checks (syntax + lint + format + test) |
+| `npm run syntax`       | Check source files for syntax errors           |
+| `npm run lint`         | Lint code (oxlint)                             |
+| `npm run format`       | Format code (oxfmt)                            |
+| `npm run format:check` | Check code formatting                          |
+| `npm run package`      | Package extension as `.vsix`                   |
 
 ## Testing
 
 ```bash
 npm test     # Run all tests
-npm run ci   # Run tests + lint + format check in one step
+npm run ci   # Run syntax + lint + format + test in one step
 ```
 
 Tests use [Vitest](https://vitest.dev/).

package.json

@@ -25,8 +25,9 @@
   "main": "./src/extension.js",
   "scripts": {
     "vscode:prepublish": "npm run ci",
-    "ci": "npm run test && npm run lint && npm run format:check",
+    "ci": "npm run syntax && npm run lint && npm run format:check && npm run test",
     "test": "vitest run",
+    "syntax": "node -e \"for(const f of require('fs').readdirSync('src').filter(n=>n.endsWith('.js')))require('child_process').execSync('node --check src/'+f,{stdio:'inherit'})\"",
     "lint": "oxlint --deny-warnings src/ tests/",
     "lint:fix": "oxlint --deny-warnings src/ tests/ --fix",
     "format": "oxfmt --write .",