refactor: Improve API design with RESTful conventions and Rails crede…

[cloudwi]

…ntials

API Changes:

• Change POST /places/:id/like to POST /places/:place_id/likes for better REST semantics
• Split PlacesController to separate concerns (PlacesController + PlaceLikesController)
• Allow users to like any place, not just their own places
• Remove authentication from external search endpoint for public access

Code Quality Improvements:

• Migrate from .env to Rails credentials for secure configuration management
• Add SQL injection protection to search queries with sanitize_sql_like
• Remove obsolete Folder model association from User model
• Update Swagger documentation to reflect new API structure

Testing:

• Create comprehensive RSpec test suite with 24 examples
• Add test environment credentials for proper JWT authentication in tests
• Fix nullable field schemas in Swagger specs
• All tests passing (26 examples, 0 failures)
• Rubocop lint checks passing