Contract-first API with DTOs, validation, and server-side OpenAPI post-processing

Add dedicated request/response DTOs for all controllers, replacing raw
JsonNode parameters with validated types. Move OpenAPI path-prefix stripping
and ProcessorNode children injection into OpenApiCustomizer beans so the
spec served at /api/v1/api-docs is already clean — eliminating the need for
the ui/scripts/process-openapi.mjs post-processing script.

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

ui/src/components/command-palette/ResultItem.tsx

@@ -1,4 +1,4 @@
-import type { ExecutionSummary, AgentInstance } from '../../api/schema-types';
+import type { ExecutionSummary, AgentInstance } from '../../api/types';
 import type { PaletteResult, RouteInfo } from './use-palette-search';
 import { highlightMatch, formatRelativeTime } from './utils';
 import { AppBadge } from '../shared/AppBadge';

ui/src/components/command-palette/use-palette-search.ts

@@ -1,6 +1,6 @@
 import { useQuery } from '@tanstack/react-query';
 import { api } from '../../api/client';
-import type { ExecutionSummary, AgentInstance } from '../../api/schema-types';
+import type { ExecutionSummary, AgentInstance } from '../../api/types';
 import { useCommandPalette, type PaletteScope } from './use-command-palette';
 import { useDebouncedValue } from './utils';
 
@@ -51,7 +51,7 @@ export function usePaletteSearch() {
         },
       });
       if (error) throw new Error('Search failed');
-      return data as unknown as { data: ExecutionSummary[]; total: number };
+      return data!;
     },
     enabled: isOpen && isExecutionScope(scope),
     placeholderData: (prev) => prev,
@@ -64,7 +64,7 @@ export function usePaletteSearch() {
         params: { query: {} },
       });
       if (error) throw new Error('Failed to load agents');
-      return data as unknown as AgentInstance[];
+      return data!;
     },
     enabled: isOpen && (isApplicationScope(scope) || isRouteScope(scope)),
     staleTime: 30_000,