v0.4.0a1 — chunkshop 0.6.1, online embedding migration, code-graph queries

Alpha release. Additive and backward-compatible — existing query/ingest behavior is unchanged (retrieval path untouched); validated against a 2.5 GB real corpus with no accuracy change.

Highlights

Online embedding-model migration — pgrg migrate-embeddings prepare/backfill/build-index/status/cutover/finalize. Change the embedding model/dimension on a live database via an expand/contract column swap: no parallel DB, online resumable backfill, brief atomic cutover. A startup guard (EmbeddingDimMismatch) fails fast if embedding_dim no longer matches the live column. See docs/cookbook/changing-embedding-dimensions.md.

Code-graph queries — pgrg code-impact <fqn> and GraphRAG.code_impact(...) report a code symbol's callers/callees (with evidence) over the existing relationships graph — cycle-safe recursive CTEs, --depth for transitive impact, tree or --json.

Chunkshop 0.6.1 code surfaces — dependency floor 0.5.0 → 0.6.1. chunkshop:code_aware / chunkshop:symbol_aware chunkers; pgrg ingest-chunkshop-table (+ --with-code-edges); code_summary → CODE_SYMBOL description enrichment; top_terms folded into the chunk full-text search_vector.

Hardening — if_oversize fallback in chunkshop delegation; clear error when importing code_edges from a schema without the table.

Notes

• lede / lede-spacy stay at >=0.4.5 (current latest).
• Re-running an embedding migration is data-safe; embedding_old is preserved until finalize.

Full details in CHANGELOG.md (0.4.0a1).