ext-v0.5.10

Automated extension build (Chrome + Firefox zips). NOT yet submitted to any store — promote deliberately via extension-submit-cws (Chrome) / extension-submit-amo (Firefox). See docs/extension-rollout.md.

What's Changed

• B101/P0: Stats/Meta data foundation — extraction, schema, persistence, upload wiring, backfill by @pmossman in #7

Full Changelog: ext-v0.5.9...ext-v0.5.10