Add a ConfigContext and replace all inlined event copy

[Kaushik4141]

New apps/web/src/contexts/ConfigContext.tsx fetches GET /api/v1/settings once at boot, holds it in context, and exposes useConfig(). Wrap <App /> in main.tsx.

Show a spinner until it resolves. If the fetch fails, show a setup-help message naming the likely cause — a misconfigured VITE_API_URL — rather than a blank screen. That error path is most of the value here, since it is the first thing a self-deployer will hit.

Then replace the inlined copy

Each string becomes its config value, and the surrounding block hides when the value is null.

• LoginScreen.tsx:39 event name, :51-53 tagline
• ProgressScreen.tsx:69 logo, :76 award name, :81 "Stall Directory", :135 "all 11 stalls", :155 "All Stalls Rated!"
• RatingScreen.tsx:66, :84, :87, :266
• RatingScreen.tsx:270 — drop the "Innovating sustainable hardware…" fallback entirely; render nothing when the description is empty
• CompletionScreen.tsx:72 (11/11), :82-83
• ScannerScreen.tsx:143-144, :169
• App.tsx:121, :260

Page title

• apps/web/index.html:7 is still <title>web</title>, the Vite default

The title must be in the served HTML before JS runs, so it cannot come from the runtime fetch. Use a small Vite HTML transform fed by a VITE_APP_NAME build var, and add <meta name="description"> and og:title from the same source.

Blocked by the settings issue.