fix(web): settings shows on first load + global DemoProvider

[offendingcommit]

Summary

Two bugs in packages/web:

Bug 1 — Blank screen on first load

__root.tsx called loadConfig() synchronously, returned null if no config existed, and only fired router.navigate({ to: '/settings' }) from a useEffect. The first paint was empty until the effect ran (and on StrictMode double-invoke + scheduling, often required a manual refresh to surface the settings page).

Fix: moved the redirect into the root route's beforeLoad, so the redirect resolves synchronously during route loading and the settings form is the first thing rendered.

Bug 2 — DemoProvider not globally available

<DemoProvider> was mounted inside RootLayout after the if (!config) return null early return and only on the non-settings branch. Any consumer of useDemo() outside that branch would throw useDemoContext must be used within DemoProvider.

Fix: hoisted <DemoProvider> up into main.tsx so the context wraps the entire app (settings route included).

Tests

Added packages/web/vitest.config.ts, jsdom setup, and src/test/app.test.tsx:

• first load with no config > renders the settings form on first paint when no config exists — fails before the fix (empty body), passes after.
• Sidebar/useDemo availability across routes > does not throw when a useDemo consumer mounts alongside the routed app — guards the global-provider wiring.

Confirmed both tests fail for the right reason on the unfixed code, then pass after the fix.

Test plan

• pnpm --filter @openconcho/web test
• pnpm --filter @openconcho/web typecheck
• pnpm --filter @openconcho/web build
• Manual: clear localStorage, reload / → settings form visible immediately, no refresh needed.
• Manual: save config, navigate to /settings, no useDemoContext console error.

Notes

• pnpm lint is broken on main due to a pre-existing biome config / version mismatch (biome.json uses 2.x keys, installed biome is 1.9.4). Not addressed here to keep the PR scoped — flag for follow-up.
• Playwright e2e was not added; the workspace has no existing playwright setup and adding it expanded scope beyond the bug fixes. The unit tests cover the regressions.