fix: report Faro app name as dancefinder-app (#3107)

Faro reported the app as `Shiny Frontend` (copied from Shiny). Dancefinder's browser logs and traces would then mix with Shiny's in VictoriaLogs/VictoriaTraces once shiny/frontend#3778 moves to faro.unbound.se.

- `app.name`: `Shiny Frontend` → `dancefinder-app`. This follows the backend convention, where the OTel `service.name` is the repo name (`dancefinder`).
- `version` (`1.0.0`, the same as package.json) and `environment` (`config.name`) are unchanged.

`npm run lint` passes.

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https://claude.ai/code/session_01VSC7dLAgao1afzL5DQfH8F
Reviewed-on: #3107

app/plugins/01.grafana.ts

@@ -9,7 +9,7 @@ export default defineNuxtPlugin((nuxtApp) => {
   if (config.grafanaUrl) {
     const faro = initializeFaro({
       app: {
-        name: 'Shiny Frontend',
+        name: 'dancefinder-app',
         version: '1.0.0',
         environment: config.name,
       },