Add Claude Pro/Max, Mistral, Cerebras and OpenRouter connectors

Closes the Anthropic OAuth gap with a native Claude Pro/Max device sign-in
(reusing the OAuth engine) and adds three OpenAI-compatible API-key
providers. Model lists are sourced from the provider registry. A backfill
migration seeds the new providers into existing organizations idempotently.

AgentCompany-New/src/main/database/schema.ts

@@ -34,6 +34,7 @@ import { browserActionMetadataSchema } from "./migrations/032-browser-action-met
 import { auditEventImmutabilitySchema } from "./migrations/033-audit-event-immutability";
 import { providerAuthSessionsSchema } from "./migrations/034-provider-auth-sessions";
 import { taskRunIsolationSchema } from "./migrations/035-task-run-isolation";
+import { additionalConnectorsSchema } from "./migrations/036-additional-connectors";
 
 interface Migration {
   version: number;
@@ -77,6 +78,7 @@ const MIGRATIONS: Migration[] = [
   { version: 33, name: "audit_event_immutability", sql: auditEventImmutabilitySchema },
   { version: 34, name: "provider_auth_sessions", sql: providerAuthSessionsSchema },
   { version: 35, name: "task_run_isolation", sql: taskRunIsolationSchema },
+  { version: 36, name: "additional_connectors", sql: additionalConnectorsSchema },
 ];
 
 const SCHEMA_VERSION = MIGRATIONS[MIGRATIONS.length - 1].version;