fix: reindex embeddings after config drift

[YOMXXX]

Summary

• Wire store init reindex detection to reindexAll() when embedding provider/model/dimensions drift is reported.
• Run reindex in initStores() so both live TdaiCore and shared createPipeline/seed paths refresh existing L1/L0 vectors.
• Clear the returned reindex flag after a successful reindex and log progress/completion.

Root cause

VectorStore.init() already returns needsReindex after recreating vec tables, but the shared store initialization path did not execute reindexAll(), so historical records could remain without fresh vectors after embedding config drift.

Tests

• RED: npm test -- src/utils/pipeline-factory.test.ts failed because reindexAll was called 0 times.
• GREEN: npm test -- src/utils/pipeline-factory.test.ts
• npm test
• npm run build

Refs #164.
Related #200.

[Maxwell-Code07]

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