Story 1.2: Config Priority Merging #4
Description
As a package developer,
I want configs from multiple sources to merge with clear priority rules,
So that users can override defaults without editing package files.
Acceptance Criteria:
- Given the same config key exists in multiple sources (e.g., package default, user home, working directory)
- When configs are merged
- Then the value from the highest priority source is used (explicit path > working dir > user home > package defaults)
- And only the conflicting keys are overridden; non-conflicting keys from all sources are preserved