feat(ui): Explorer interactivity — detail views, richer tables, Sales charts, cross-filtering (PRP-20)

[w7-mgfcode]

Implements PRP-20 — PRPs/PRP-20-explorer-interactivity.md.

Turns the three primary Explorer pages (Sales, Stores, Products) from flat read-only views into an interactive analysis surface.

Scope

• Click-through detail views — two deep-linkable routes (/explorer/stores/:storeId, /explorer/products/:productId): entity profile, date-scoped KPIs, revenue-over-time chart, top-contributors drilldown.
• Richer tables — server-side column sorting, CSV export, column-visibility toggles on Stores / Products / Runs.
• Charts on Sales — revenue-by-dimension bar chart + revenue-over-time line chart alongside the ranked list.
• Cross-filtering — filter / date / dimension state persisted in the URL; "View in Sales" link carries store_id / product_id.

Backend (additive — no migration, no new slice, no app/main.py change, no .env var)

• GET /analytics/timeseries — daily/weekly/monthly/quarterly aggregated sales, filterable by store_id / product_id / category.
• GET /dimensions/stores and /dimensions/products gain optional allow-listed sort_by / sort_order query params.
• Also closes the analytics slice test gap (no test files today).

Maintainer-confirmed decisions (2026-05-18)

1. All four interactivity directions ship (detail views, richer tables, Sales charts, cross-filtering).
2. Time-series data via a dedicated GET /analytics/timeseries endpoint, not reused /analytics/drilldowns.
3. Entity detail views are dedicated React Router route pages (deep-linkable), not Sheet/Dialog.

Task checklist

• Task 1 — Open this tracking issue
• Task 2 — Backend: GET /analytics/timeseries endpoint (schemas + service + routes)
• Task 3 — Backend: sort_by / sort_order on /dimensions store + product listings
• Task 4 — Backend tests (analytics + dimensions DB fixtures, closes the test gap)
• Task 5 — Frontend: types + hooks (use-timeseries, use-lifecycle-curve, sort params)
• Task 6 — Frontend: shared interactive components (view-options, column-header, revenue-bar-chart, csv-export)
• Task 7 — Frontend: routing (2 lazy detail routes)
• Task 8 — Frontend: store + product detail pages
• Task 9 — Frontend: richer Stores + Products tables
• Task 10 — Frontend: Runs table (export + view-options)
• Task 11 — Frontend: Sales page charts + cross-filtering
• Task 12 — Frontend test (csv-export.test.ts)
• Task 13 — Docs: README + API_CONTRACTS + REPO_MAP_INDEX
• Task 14 — Dogfood the running UI (webapp-testing / agent-browser, screenshots)
• Task 15 — Commit + PR into dev

No Alembic migration. No new slice. No app/main.py change. No new .env var.

[w7-mgfcode]

Resolved on dev by 6debbeb feat(ui): Explorer interactivity — detail views, richer tables, Sales charts, cross-filtering (PRP-20) (#188). Store/product detail pages, GET /analytics/timeseries, dimensions sort params, and csv-export.test.ts are all merged. Closing as completed (PR #188 did not back-reference this tracking issue).