Add Scaleway, Yousign, Railway and Crisp access-review connectors

Four API-key, single-tenant (Pattern 3) connectors:

- Scaleway: secret key in the X-Auth-Token header plus an Organization ID
  setting; GET /iam/v1alpha1/users (owner/member, status, two-factor),
  per-connection BuildProbeURL.
- Yousign: Bearer API key; GET /v3/users (admin/owner/member, is_active);
  production host with a static probe.
- Railway: Bearer account token; GraphQL me{workspaces{members}} aggregated
  and deduplicated across workspaces; custom probe, since Railway returns
  HTTP 200 with an errors body on a rejected token.
- Crisp: plugin token as HTTP Basic (identifier:key) plus a Website ID
  setting and the X-Crisp-Tier header; GET /v1/website/{id}/operators/list,
  custom probe and name resolver.

Scaleway and Crisp carry a required extra setting, so the console add-source
dialog maps organizationId/websiteId onto their scalewayOrganizationId and
crispWebsiteId API-key inputs; without that mapping the value is silently
dropped and the create is rejected.

Cassette-backed driver tests plus unit tests for the cross-workspace
deduplication, the probe contracts and the role/MFA helpers.

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

pkg/coredata/connector_provider.go

@@ -74,6 +74,10 @@ const (
 	ConnectorProviderOpenRouter   ConnectorProvider = "OPENROUTER"
 	ConnectorProviderIncidentIO   ConnectorProvider = "INCIDENT_IO"
 	ConnectorProviderBrevo        ConnectorProvider = "BREVO"
+	ConnectorProviderScaleway     ConnectorProvider = "SCALEWAY"
+	ConnectorProviderYousign      ConnectorProvider = "YOUSIGN"
+	ConnectorProviderRailway      ConnectorProvider = "RAILWAY"
+	ConnectorProviderCrisp        ConnectorProvider = "CRISP"
 )
 
 var (
@@ -135,6 +139,10 @@ func ConnectorProviders() []ConnectorProvider {
 		ConnectorProviderOpenRouter,
 		ConnectorProviderIncidentIO,
 		ConnectorProviderBrevo,
+		ConnectorProviderScaleway,
+		ConnectorProviderYousign,
+		ConnectorProviderRailway,
+		ConnectorProviderCrisp,
 	}
 }
 
@@ -191,7 +199,11 @@ func (v ConnectorProvider) IsValid() bool {
 		ConnectorProviderPylon,
 		ConnectorProviderOpenRouter,
 		ConnectorProviderIncidentIO,
-		ConnectorProviderBrevo:
+		ConnectorProviderBrevo,
+		ConnectorProviderScaleway,
+		ConnectorProviderYousign,
+		ConnectorProviderRailway,
+		ConnectorProviderCrisp:
 		return true
 	}