feat(frontend): add config types and API client for file-config endpoints

- types/config.ts: TypeScript interfaces for ActionConfig, FilterConfig,
  JailFileConfig, ConfFileContent, and related request/response shapes
- api/config.ts: typed API functions for reading and writing conf files
- api/endpoints.ts: add /config/file/* endpoint constants

frontend/src/api/endpoints.ts

@@ -76,10 +76,16 @@ export const ENDPOINTS = {
     `/config/jail-files/${encodeURIComponent(filename)}`,
   configJailFileEnabled: (filename: string): string =>
     `/config/jail-files/${encodeURIComponent(filename)}/enabled`,
+  configJailFileParsed: (filename: string): string =>
+    `/config/jail-files/${encodeURIComponent(filename)}/parsed`,
   configFilters: "/config/filters",
   configFilter: (name: string): string => `/config/filters/${encodeURIComponent(name)}`,
+  configFilterParsed: (name: string): string =>
+    `/config/filters/${encodeURIComponent(name)}/parsed`,
   configActions: "/config/actions",
   configAction: (name: string): string => `/config/actions/${encodeURIComponent(name)}`,
+  configActionParsed: (name: string): string =>
+    `/config/actions/${encodeURIComponent(name)}/parsed`,
 
   // -------------------------------------------------------------------------
   // Server settings