Add OIDC logout, fix OpenAPI schema types, expose end_session_endpoint

Backend:
- Expose end_session_endpoint from OIDC provider metadata in /auth/oidc/config
- Add getEndSessionEndpoint() to OidcTokenExchanger

Frontend:
- On OIDC logout, redirect to provider's end_session_endpoint to clear SSO session
- Strip /api/v1 prefix from OpenAPI paths to match client baseUrl convention
- Add schema-types.ts with convenience type re-exports from generated schema
- Fix all type imports to use schema-types instead of raw generated schema
- Fix optional field access (processors, children, duration) with proper typing
- Fix AgentInstance.state → status field name

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/executions/ResultsTable.tsx

@@ -1,5 +1,5 @@
 import { useState, useMemo } from 'react';
-import type { ExecutionSummary } from '../../api/schema';
+import type { ExecutionSummary } from '../../api/schema-types';
 import { StatusPill } from '../../components/shared/StatusPill';
 import { DurationBar } from '../../components/shared/DurationBar';
 import { AppBadge } from '../../components/shared/AppBadge';