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/coredata/connector_provider.go

@@ -65,6 +65,11 @@ const (
 	ConnectorProviderQovery       ConnectorProvider = "QOVERY"
 	ConnectorProviderRender       ConnectorProvider = "RENDER"
 	ConnectorProviderNeon         ConnectorProvider = "NEON"
+	ConnectorProviderMercury      ConnectorProvider = "MERCURY"
+	ConnectorProviderApollo       ConnectorProvider = "APOLLO"
+	ConnectorProviderDeepgram     ConnectorProvider = "DEEPGRAM"
+	ConnectorProviderClickHouse   ConnectorProvider = "CLICKHOUSE"
+	ConnectorProviderLangfuse     ConnectorProvider = "LANGFUSE"
 )
 
 var (
@@ -117,6 +122,11 @@ func ConnectorProviders() []ConnectorProvider {
 		ConnectorProviderQovery,
 		ConnectorProviderRender,
 		ConnectorProviderNeon,
+		ConnectorProviderMercury,
+		ConnectorProviderApollo,
+		ConnectorProviderDeepgram,
+		ConnectorProviderClickHouse,
+		ConnectorProviderLangfuse,
 	}
 }
 
@@ -164,7 +174,12 @@ func (v ConnectorProvider) IsValid() bool {
 		ConnectorProviderZendesk,
 		ConnectorProviderQovery,
 		ConnectorProviderRender,
-		ConnectorProviderNeon:
+		ConnectorProviderNeon,
+		ConnectorProviderMercury,
+		ConnectorProviderApollo,
+		ConnectorProviderDeepgram,
+		ConnectorProviderClickHouse,
+		ConnectorProviderLangfuse:
 		return true
 	}