refactor: move collection reactions into store integration

[hhhjin]

Summary

• move workspace-to-collection coupling behind typed store events and a dedicated collection integration
• emit narrow workspace tree events for entry replacement, create, delete, rename, and move operations
• update store tests to assert event emission and integration behavior instead of direct collection port calls

Review

• review gate found no actionable issues in the published scope

Testing

• pnpm lint:fix
• pnpm --filter @mdit/store test
• pnpm --filter @mdit/store ts:check

Notes

• excluded local untracked notes under todos/ from this PR scope

[gemini-code-assist]

Code Review

This pull request refactors the collection management logic to use an event-driven architecture, replacing direct port calls with workspace event emissions. It introduces a new integration to handle events such as entry creation, deletion, renaming, and moving, while updating the collection slice to correctly process file-level changes. Feedback highlights a potential race condition due to unawaited event emissions in the tree actions and suggests aligning the onEntryCreated method signature with other event handlers for consistency.