When merging user and project configs, categories were simply
spread instead of deep merged. This caused user-level category
model settings to be completely overwritten by project-level
configs, even when the project config only specified partial
overrides like temperature.
Add deepMerge for categories field and comprehensive tests.
Reduce index.ts from 724 to 458 lines (37% reduction):
- Extract config loading to plugin-config.ts
- Extract ModelCacheState to plugin-state.ts
- Extract config handler to plugin-handlers/config-handler.ts
All 408 tests pass, TypeScript typecheck clean.
🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)