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/use-execution-search.ts

@@ -1,5 +1,5 @@
 import { create } from 'zustand';
-import type { SearchRequest } from '../../api/schema';
+import type { SearchRequest } from '../../api/schema-types';
 
 function todayMidnight(): string {
   const d = new Date();
@@ -94,8 +94,8 @@ export const useExecutionSearch = create<ExecutionSearchState>((set, get) => ({
       status: statusStr ?? undefined,
       timeFrom: s.timeFrom ? new Date(s.timeFrom).toISOString() : undefined,
       timeTo: s.timeTo ? new Date(s.timeTo).toISOString() : undefined,
-      durationMin: s.durationMin,
-      durationMax: s.durationMax,
+      durationMin: s.durationMin ?? undefined,
+      durationMax: s.durationMax ?? undefined,
       text: s.text || undefined,
       routeId: s.routeId || undefined,
       agentId: s.agentId || undefined,