## Context\n\nNo integration tests exist for BlockStore, making it difficult to catch regressions.\n\n## Goal\n\nAdd BlockStore integration tests to catch regressions.\n\n## Implementation\n\n- File: Create src/stores/__tests__/blockStore.integration.test.ts\n- Test block mutation patterns (create, indent, merge)\n- Effort: 6h\n\n## Impact\n\nCatch regressions in BlockStore mutations.\n\n## References\n\n- ARCHITECTURE_REVIEW.md Section 9, Wave 3, Item 12\n- Issue Catalog (BlockStore tests)
