feat: add dark mode toggle to settings

fix: correct spelling of CHANGELOG

docs: update installation instructions in README

feat!: drop support for Node 6

feat(lang): add Polish language support

fix(parser): handle edge case with empty arrays

feat(api): add new user authentication endpoint

style(ui): fix button styling on mobile devices

feat: allow provided config object to extend other configs

This commit enables configuration objects to extend other config files,
improving code reusability and reducing duplication across projects.

The implementation uses a new `extends` key in the config file that can
reference other configuration files by path or package name.

Closes #42

fix: prevent racing of requests

Introduce a request id and a reference to latest request. Dismiss
incoming responses other than from latest request.

Remove timeouts which were used to mitigate the racing issue but are
obsolete now.

Reviewed-by: Z
Refs: #123

feat(api)!: send an email to the customer when a product is shipped

chore!: drop support for Node 6

BREAKING CHANGE: use JavaScript features not available in Node 6.

feat(auth)!: change authentication flow

This commit modifies the authentication flow to use OAuth2 instead of
session-based authentication. Existing API clients will need to update
their authentication mechanism.

BREAKING CHANGE: authentication now requires OAuth2 tokens instead of session cookies

fix: prevent racing of requests

Introduce a request id and a reference to latest request. Dismiss
incoming responses other than from latest request.

Remove timeouts which were used to mitigate the racing issue but are
obsolete now.

Reviewed-by: Z
Refs: #123
Closes: #456

feat(ui): add theme customization panel
feat(api): implement user profile API endpoints
feat(docs): add API documentation with examples
feat(perf): optimize database query performance

fix(auth): resolve login page refresh issue
fix(parser): handle null values in array parsing
fix(ui): correct button alignment on mobile
fix(api): return correct status code for 404 errors

docs: update CONTRIBUTING.md with new guidelines
docs(api): document new authentication endpoints
docs: add deployment instructions for Docker

refactor(core): simplify request processing logic
refactor(utils): consolidate duplicate functions
refactor(db): reorganize database query builders

test: add comprehensive coverage for auth module
test(parser): add test cases for edge cases
test: improve test isolation and reliability

chore: upgrade dependencies to latest versions
chore(build): update webpack configuration
chore: configure pre-commit hooks

ci: add GitHub Actions workflow for tests
ci: configure automatic deployment to staging
ci(coverage): add code coverage reporting

style: fix indentation in authentication module
style(utils): apply formatting rules to all files
style: remove trailing whitespace

perf: optimize image loading with lazy loading
perf(api): reduce database query time by 40%
perf: implement result caching for expensive operations

feat(payment): add Stripe payment integration

Integrate Stripe payment processing into the checkout flow. This allows
customers to pay for orders using various payment methods supported by
Stripe.

Changes:
- Add Stripe API client initialization
- Implement payment form component
- Add payment processing endpoint
- Store payment tokens securely
- Add error handling for payment failures

Testing:
- Unit tests for payment processing logic
- Integration tests for checkout flow
- Manual testing with Stripe test account

Related Issues: closes #789, relates to #790

fix(auth): prevent session hijacking vulnerability

The session token was not being properly validated on each request,
allowing attackers to reuse expired tokens. This commit adds proper
token validation and expiration checking.

Security Impact: High - potential for unauthorized access
Affected Versions: all versions before v2.1.0

Testing:
- Security audit passed
- All auth tests passing
- Manual testing with token expiration scenarios

Reviewed-by: security@company.com
Refs: #999

feat!: migrate to new configuration format

Configuration format has changed from XML to YAML for better readability
and easier maintenance. Old XML configurations will not be supported
after v3.0.0.

Migration Path:
1. Use provided migration tool: `migrate-config --xml-to-yaml config.xml`
2. Update application initialization code
3. Test thoroughly before deploying to production

For more details, see MIGRATION.md

BREAKING CHANGE: XML configuration format no longer supported, use YAML instead
Deprecated: old ConfigParser class, use new YAMLConfigParser

fix: bug
feat: improvements

fix: resolve null pointer exception in user lookup
feat: add email notification for order status changes

allow users to toggle dark mode

feat: allow users to toggle dark mode

feat: added dark mode support
fix: fixed the login issue

feat: add dark mode support
fix: resolve login issue

feat: Add Dark Mode Support
fix: Resolve Login Issue

feat: add dark mode support
fix: resolve login issue