Support a custom API-key auth header in connections

The API-key connection always presented the key as Authorization:
Bearer. Some providers, notably Anthropic, require the key in a custom
header such as x-api-key and reject Bearer auth, returning 400 when
both headers are present.

Add an optional Header field on APIKeyConnection (empty preserves the
Bearer default for every existing provider) served by a small transport
that omits Authorization, plus a registry-declared APIKeyHeader so the
create-connector resolver wires the right scheme per provider.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/server/api/console/v1/connector_resolvers.go

@@ -40,7 +40,10 @@ func (r *mutationResolver) CreateAPIKeyConnector(ctx context.Context, input type
 		OrganizationID: input.OrganizationID,
 		Provider:       input.Provider,
 		Protocol:       coredata.ConnectorProtocolAPIKey,
-		Connection:     &connector.APIKeyConnection{APIKey: input.APIKey},
+		Connection: &connector.APIKeyConnection{
+			APIKey: input.APIKey,
+			Header: r.providerRegistry.APIKeyHeader(input.Provider),
+		},
 	}
 
 	raw, err := apiKeyConnectorSettings(input)