feat(api): include providerName in GET /api/connections

[matoushavlena]

Summary

Fold the app-registry display name into the /api/connections response so external callers (e.g. the Humr agent platform) don't have to make a second request to /api/apps just to render "Google Drive" next to the user's email.

Why

The existing connection.label field is the user's identity — extractLabel() in connection-service.ts derives it from metadata.email | username | name. It is not the app's display name. When callers render label as the card title, the result is a duplicated email on both lines (see kagenti/humr#187 for the before-screenshot).

The display name ("Google Drive", "Gmail", "GitHub") already lives in the static apps registry. Joining on the server is a one-line map.

What

+import { apps } from "@/lib/apps/registry";
 ...
+const providerName = new Map(apps.map((a) => [a.id, a.name]));
 const connections = await listConnections(auth.accountId);
-return NextResponse.json(connections);
+const enriched = connections.map((c) => ({
+  ...c,
+  providerName: providerName.get(c.provider) ?? null,
+}));
+return NextResponse.json(enriched);

Compatibility

Pure additive — no field removed, no type change. Existing consumers (OneCLI dashboard, Humr) keep working. When the provider id isn't in the registry (unlikely, but possible if a connection is orphaned after an app is removed), providerName is null so callers can fall back.

Test plan

• Smoke: GET /api/connections returns rows with providerName populated for registry-backed providers.
• Regression: existing clients ignoring the new field continue to work unchanged.