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/shared/provider-catalog.ts

@@ -20,6 +20,15 @@ const RAW_CATALOG: Omit<ProviderCatalogEntry, "models">[] = [
     signInUrl: null,
     credentialHelp: "Generate an API key at console.anthropic.com → API keys.",
   },
+  {
+    key: "claude-pro",
+    label: "Claude Pro/Max",
+    authType: PROVIDER_AUTH_TYPE.OAUTH_PKCE,
+    defaultModel: "claude-sonnet-4-5",
+    capabilityTags: ["account", "subscription"],
+    signInUrl: "https://claude.ai/login",
+    credentialHelp: "Sign in with your Claude Pro or Max account in the browser; AgentCompany finishes the handshake.",
+  },
   {
     key: "xai",
     label: "xAI Grok",
@@ -38,6 +47,33 @@ const RAW_CATALOG: Omit<ProviderCatalogEntry, "models">[] = [
     signInUrl: null,
     credentialHelp: "Generate an API key at console.groq.com → API keys.",
   },
+  {
+    key: "mistral",
+    label: "Mistral",
+    authType: PROVIDER_AUTH_TYPE.API_KEY,
+    defaultModel: "mistral-large-latest",
+    capabilityTags: ["chat", "reasoning"],
+    signInUrl: null,
+    credentialHelp: "Generate an API key at console.mistral.ai → API keys.",
+  },
+  {
+    key: "cerebras",
+    label: "Cerebras",
+    authType: PROVIDER_AUTH_TYPE.API_KEY,
+    defaultModel: "qwen-3-235b-a22b-instruct-2507",
+    capabilityTags: ["inference", "fast"],
+    signInUrl: null,
+    credentialHelp: "Generate an API key at cloud.cerebras.ai → API keys.",
+  },
+  {
+    key: "openrouter",
+    label: "OpenRouter",
+    authType: PROVIDER_AUTH_TYPE.API_KEY,
+    defaultModel: "anthropic/claude-sonnet-4.5",
+    capabilityTags: ["router", "multi-model"],
+    signInUrl: null,
+    credentialHelp: "Generate an API key at openrouter.ai → Keys.",
+  },
   {
     key: "github-copilot",
     label: "GitHub Copilot",