MM-64282 E2E/Playwright: Test documentation format (#31050)

* initial implementation of test documentation in spec file with AI-assisted prompt from Claude and linter script

* update snapshots

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/playwright/script/README.md

@@ -0,0 +1,62 @@
+# Playwright E2E Test Scripts
+
+This directory contains utility scripts for the Playwright E2E test suite.
+
+## Test Documentation Format Linter
+
+The `lint-test-docs.js` script verifies that all spec files follow the required documentation format:
+
+- JSDoc with `@objective` and `@precondition` tags
+- Proper test title with MM-T ID (e.g., MM-T1234)
+- Tag for feature categorization (e.g., `{tag: '@feature_name'}`)
+- Action comments (e.g., `// # Action`)
+- Verification comments (e.g., `// * Verification`)
+
+### Usage
+
+```bash
+# Run the linter directly
+node script/lint-test-docs.js
+
+# Or use the npm script
+npm run lint:test-docs
+```
+
+### Integration with CI
+
+The linter is also integrated with the main `check` command, which is typically run before committing changes:
+
+```bash
+npm run check
+```
+
+This will run ESLint, Prettier, TypeScript type checking, and the test documentation format linter.
+
+### Requirements
+
+All spec files should follow this format:
+
+```typescript
+/**
+ * @objective Clear description of what the test verifies
+ *
+ * @precondition
+ * Special setup or conditions required for the test
+ * Note: Only include for non-default requirements
+ */
+test('descriptive test title', {tag: '@feature_tag'}, async ({pw}) => {
+    // # Initialize setup and login
+    const {user} = await pw.initSetup();
+    const {channelsPage} = await pw.testBrowser.login(user);
+
+    // # Navigate to channel and post a message
+    await channelsPage.goto();
+    await channelsPage.postMessage('Test message');
+
+    // * Verify message appears in the channel
+    const lastPost = await channelsPage.getLastPost();
+    await expect(lastPost.body).toContainText('Test message');
+});
+```
+
+This ensures consistency across all test files and makes it easier to understand the purpose and requirements of each test.