[dbccpage]

This makes the one-screen BQNF overview Jeremy approved the front page at /. It uses the same pattern as the SmplCache front page:

• What's on it: four changes to a small sales table, with id first. The stored SUM and MAX sit next to the table's real answer.
• Comparison: what a SQL Server indexed view (which can't contain MAX), a Postgres materialized view (stale until REFRESH) and BQNF each do with every change.
• The hook: deleting the current MAX. With the extra state (each region's amounts, sorted), BQNF fixes it in place. With that state switched off, it rescans only the affected group.
• Source of the values: they match the repo's own BQNF simulator, the financial_ledger preset. With use_cochain on it routes Repair, and with it off it routes Recompute.

The full Studio moves to /studio/, and /studio redirects there with a 308. The overview's header links to the Studio, and the Studio's header links back.

Changes:

• web/templates/overview.html: the overview, served as plain HTML through FileResponse, not Jinja.
• web/app.py: adds the /, /studio and /studio/ routes.
• web/templates/index.html: adds an "Overview" link to the header.
• Tests: web/test_api_smoke.py and tests/test_web_api.py now check the overview at / and the Studio at /studio/.
• scripts/browser_smoke.cjs: opens /studio/ and checks that both pages are served exactly as committed.

Checks:

• pytest tests web/test_api_smoke.py: 232 passed.
• I opened the overview once in Chromium under local uvicorn. It showed no console errors and no horizontal overflow at 1280px.
• The browser smoke script fails here on 21 checks. The same 21 fail on main in this sandbox, because the Tailwind CDN is blocked here. CI runs it for real.

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Generated by Claude Code