feat(backend): add claude runtime, anthropic OAuth auth kind, and profile→runtime derivation

packages/backend/convex/runtimeSupport.ts

@@ -0,0 +1,23 @@
+import type { Doc } from './_generated/dataModel';
+
+export type AgentRuntimeName = 'codex' | 'opencode' | 'claude';
+
+// Which runtimes a provider profile can drive.
+export const runtimesForProfile = (
+  profile: Pick<Doc<'aiProviderProfiles'>, 'provider' | 'authType'>,
+): AgentRuntimeName[] => {
+  if (
+    profile.provider === 'opencode_openai_login' ||
+    profile.authType === 'opencode_auth_json'
+  ) {
+    return ['codex']; // ChatGPT-login snapshot → Codex CLI only
+  }
+  if (profile.provider === 'anthropic') {
+    return profile.authType === 'anthropic_oauth_json'
+      ? ['claude']
+      : ['claude', 'opencode'];
+  }
+  if (profile.provider === 'openai') return ['opencode', 'codex'];
+  // Every remaining API-key provider is OpenAI-compatible → OpenCode.
+  return ['opencode'];
+};