v0.4.0

Ops & retrieval-quality pass. Public OSS-grade hygiene.

Added

• GitHub Actions CI (.github/workflows/ci.yml) — php -l matrix across
  PHP 8.0/8.1/8.2/8.3, msgfmt catalog check, PHPStan informational job,
  PHPUnit on PHP 8.1/8.2/8.3.
• Release ZIP workflow (.github/workflows/release.yml) — automatic
  clean distribution zip attached to every v* tag, with dev files excluded.
• readme.txt in the WordPress.org plugin-directory format (description,
  installation, FAQ, screenshots, changelog, upgrade notice). Ready for
  submission to wordpress.org.
• PHPStan config at level 6 with a small WP stub bootstrap. Runs in CI
  as continue-on-error for now — we publish results but don't fail PRs
  until a WordPress stub package is added.
• PHPUnit smoke tests — 35+ assertions across Vector_Store helpers
  (filter compilation, score normalisation, dedup, cache key), the
  Embedded_Connection idempotency sniff, the Metrics class, and the
  Quantization round-trip. Tests run on PHP 8.1/8.2/8.3 in CI.
• Async reprocess via Action Scheduler — MxChat_DuckDB_Async_Reprocess
  enqueues one job per post in Action Scheduler (bundled with WooCommerce
  and many WP plugins). Survives PHP max_execution_time on multi-thousand-
  post catalogs; reports progress via a single non-autoloaded state option.
  Falls back to the existing AJAX-batched path when Action Scheduler isn't
  installed. New CLI command: wp mxchat-duckdb async-reprocess.
• Pinecone → DuckDB migration tool — MxChat_DuckDB_Pinecone_Migrator
  pulls every vector + metadata directly from a Pinecone index via
  /vectors/list + /vectors/fetch and writes them into DuckDB. No
  re-embedding; pure vector copy. Resumable via a persisted pagination
  token. CLI: wp mxchat-duckdb migrate-from-pinecone --api-key=… --host=… [--namespace=…].
• Parquet export / import — Vector_Store::export_parquet() and
  import_parquet() use DuckDB's native COPY ... TO|FROM '...parquet'.
  Enables moving between embedded ⇄ MotherDuck without re-embedding,
  routine backups, and KB sharing. CLI: wp mxchat-duckdb export --path=…
  and wp mxchat-duckdb import --path=….
• INT8 quantization (experimental) — embedding_storage option toggles
  the embedding column type between FLOAT[N] (default) and TINYINT[N].
  Cuts vector storage 4×. For unit-normalised embeddings (OpenAI ada-002,
  text-embedding-3-*, Voyage, BGE) the recall loss is < 1 %.
  Score expression uses list_transform to dequantise at query time. The
  storage layout is locked once the table contains rows; switch by exporting
  to Parquet, wiping, flipping the option, re-importing.
• Vector_Store::storage_estimate() — surfaces vector count + bytes
  estimate so admins can spot when INT8 would meaningfully help.
• Packagist-ready composer.json — homepage, support URLs, keywords,
  dev-dep declarations for PHPUnit + PHPStan. Submission to packagist.org
  is a one-time manual OAuth step on the user's side.

New filters / hooks

• No new public filters in v0.4.0 — existing extension points cover the new
  features. The async path uses the existing mxchat_duckdb_post_content
  and mxchat_duckdb_sync_bot_id filters.

Notes

• Submitting to wordpress.org/plugins is a manual review process (~2–4
  weeks). The readme.txt is now compliant; you still need to add at least
  one screenshot (the settings page) and submit through the review queue.
• Submitting to packagist.org requires a one-time OAuth grant on their
  site. composer require paulargoud/mxchat-duckdb will work after that.