Enhance the booking sync logic to trim and match item names more
robustly,
falling back to creating a generic item when no host item is found. Add
unit tests for item creation and fallback behavior in booking sync.
This commit standardizes the naming of identifier and API key fields
across the codebase to use consistent camel case (e.g., `ID`, `APIKey`,
`DatabaseURL`). This includes updates to struct fields, method names,
function parameters, and environment variable references. The changes
improve code clarity and maintainability by reducing ambiguity and
aligning with Go naming conventions. No functional behavior is changed.
