Sync ShopStack 2026-06-15 round 2: primary-nav More, undo bar, freshness stamps, safe_render_html, home-flow TabContext

Upload E2E slideshow MP4

Upload E2E MP4: Docs/qa/2026-06-15_e2e_audit_run/videos_mp4/01_boot.mp4

Upload E2E video: Docs/qa/2026-06-15_e2e_audit_run/videos/04_shelf_scan.webm

Upload E2E video: Docs/qa/2026-06-15_e2e_audit_run/videos/01_boot.webm

Upload E2E video: Docs/qa/2026-06-15_e2e_audit_run/videos/e2e_recording.mp4

Sync ShopStack 2026-06-15: corrections panel, empty-state rewrite, market-source suppression

Sync ShopStack HEAD 6f8adfc

initial commit