refactor: remove deprecated apiKey from site management and update related functionality

- Removed apiKey from SiteRow type and related forms in Sites component.
- Updated site saving logic to handle site creation without apiKey.
- Adjusted tests to ensure apiKey is not included in site editor state.
- Refactored Tokens component to support embedded mode and redirect logic.
- Added migration tests for site apiKey to account migration service.
- Implemented siteApiKeyMigrationService to handle migration of apiKey to account tokens.
- Enhanced tests for segmented connections in Accounts and redirect logic for Tokens.

src/server/routes/proxy/upstreamEndpoint.ts

@@ -955,7 +955,6 @@ export async function resolveUpstreamEndpointCandidates(
         id: context.site.id,
         url: context.site.url,
         platform: context.site.platform,
-        apiKey: context.site.apiKey ?? null,
       },
       account: {
         id: context.account.id,