Add five API-key access-review connectors

Add Mercury, Apollo.io, Deepgram, ClickHouse Cloud, and Langfuse as
access-review connectors. All are API-key, single-tenant providers
(Pattern 3): the key identifies one tenant, so there is no OAuth flow,
picker UI, or bootstrap/helm configuration.

- Mercury: Bearer token, GET /api/v1/users, cursor pagination.
- Apollo.io: x-api-key header, GET /api/v1/users/search (teammates).
- Deepgram: Token scheme; lists members across every project and
  dedupes by member_id, unioning per-project scopes.
- ClickHouse Cloud: HTTP Basic (keyId:keySecret); discovers the org
  via GET /v1/organizations, then lists its members.
- Langfuse: HTTP Basic (publicKey:secretKey); a base-URL setting
  selects the regional cloud host or a self-hosted instance.

Each adds the enum value, migration, GraphQL binding, provider
Registration, a driver with a cassette-driven test, and a brand logo.

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

pkg/server/api/console/v1/graphql/connector.graphql

@@ -71,6 +71,17 @@ enum ConnectorProvider
     QOVERY @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderQovery")
     RENDER @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderRender")
     NEON @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderNeon")
+    MERCURY
+        @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderMercury")
+    APOLLO @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderApollo")
+    DEEPGRAM
+        @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderDeepgram")
+    CLICKHOUSE
+        @goEnum(
+            value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderClickHouse"
+        )
+    LANGFUSE
+        @goEnum(value: "go.probo.inc/probo/pkg/coredata.ConnectorProviderLangfuse")
 }
 
 type ConnectorProviderInfo {
@@ -152,6 +163,7 @@ input CreateAPIKeyConnectorInput {
     qoveryOrganizationId: String
     renderWorkspaceId: String
     neonOrganizationId: String
+    langfuseBaseUrl: String
 }
 
 type CreateAPIKeyConnectorPayload {