<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
- New Features
- None
- Bug Fixes
- Ensures a placeholder embedding is always created when content is
empty or after deletion, reducing errors and improving Copilot
stability.
- Refactor
- Centralized empty-embedding handling for consistent behavior across
workflows.
- Standardized embedding dimension configuration to a single source for
reliability.
- Chores
- Simplified internal embedding module surface and imports for
maintainability.
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