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/connector/provider/builtin.go

@@ -33,6 +33,7 @@ func NewBuiltinRegistry() *Registry {
 		clickhouseRegistration(),
 		clickupRegistration(),
 		cloudflareRegistration(),
+		crispRegistration(),
 		cursorRegistration(),
 		datadogRegistration(),
 		deepgramRegistration(),
@@ -62,8 +63,10 @@ func NewBuiltinRegistry() *Registry {
 		pagerdutyRegistration(),
 		pylonRegistration(),
 		qoveryRegistration(),
+		railwayRegistration(),
 		renderRegistration(),
 		resendRegistration(),
+		scalewayRegistration(),
 		sendgridRegistration(),
 		sentryRegistration(),
 		signozRegistration(),
@@ -72,6 +75,7 @@ func NewBuiltinRegistry() *Registry {
 		tailscaleRegistration(),
 		tallyRegistration(),
 		vercelRegistration(),
+		yousignRegistration(),
 		zendeskRegistration(),
 	} {
 		if err := r.Register(reg); err != nil {