feat(quality): add markdownlint-cli2 to quality checks (#1039)

- Add markdownlint-cli2 as dev dependency
- Add lint:md script to package.json
- Add markdownlint job to CI workflow
- Configure 5 rules: heading-increment, no-duplicate-heading,
  no-trailing-punctuation, no-bare-urls, no-space-in-emphasis
- Fix existing violations across 19 markdown files
- No auto-fix to prevent destructive changes

Closes #1034

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Brian <bmadcode@gmail.com>

src/modules/bmm/workflows/document-project/workflows/deep-dive-instructions.md

@@ -20,7 +20,7 @@
 
 {{#if has_api_routes}}
 
-### API Routes ({{api_route_count}} endpoints found)
+## API Routes ({{api_route_count}} endpoints found)
 
 {{#each api_route_groups}}
 {{group_index}}. {{group_name}} - {{endpoint_count}} endpoints in `{{path}}`
@@ -29,7 +29,7 @@
 
 {{#if has_feature_modules}}
 
-### Feature Modules ({{feature_count}} features)
+## Feature Modules ({{feature_count}} features)
 
 {{#each feature_modules}}
 {{module_index}}. {{module_name}} - {{file_count}} files in `{{path}}`

src/modules/bmm/workflows/testarch/ci/checklist.md

@@ -4,7 +4,7 @@
 
 - [ ] Git repository initialized (`.git/` exists)
 - [ ] Git remote configured (`git remote -v` shows origin)
-- [ ] Test framework configured (playwright.config._ or cypress.config._)
+- [ ] Test framework configured (`playwright.config._` or `cypress.config._`)
 - [ ] Local tests pass (`npm run test:e2e` succeeds)
 - [ ] Team agrees on CI platform
 - [ ] Access to CI platform settings (if updating)

src/modules/bmm/workflows/testarch/test-review/instructions.md

@@ -524,7 +524,7 @@ await expect(page.locator('[data-testid="user-menu"]')).toBeVisible({ timeout: 1
 ### 1. Use Data Factory for Test User (Lines 23, 32, 41)
 
 **Severity**: P1 (High)
-**Issue**: Hardcoded email 'test@example.com' - maintainability risk
+**Issue**: Hardcoded email `test@example.com` - maintainability risk
 **Fix**: Create factory function for test users
 **Knowledge**: See data-factories.md