feat: add CLI config preview API for Codex and Gemini

- Implemented `fetchCodexConfigPreview` and `fetchGeminiConfigPreview` functions in the API layer to retrieve masked configuration files.
- Added new interfaces `CodexConfigPreviewResponse` and `GeminiConfigPreviewResponse` to define the structure of the API responses.
- Created utility functions to read and mask sensitive values from `config.toml` and `auth.json` for Codex, and `settings.json` for Gemini.
- Updated CLI settings routes to handle new preview endpoints.
- Enhanced session content parser to support Claude JSONL format.
- Updated UI components to reflect changes in history page and navigation, including new tabs for observability.
- Localized changes for English and Chinese languages to reflect "CLI History" terminology.

ccw/frontend/src/lib/api.ts

@@ -6150,6 +6150,54 @@ export async function getCliSettingsPath(endpointId: string): Promise<{ endpoint
   return fetchApi(`/api/cli/settings/${encodeURIComponent(endpointId)}/path`);
 }
 
+// ========== CLI Config Preview API ==========
+
+/**
+ * Codex config preview response
+ */
+export interface CodexConfigPreviewResponse {
+  /** Whether preview was successful */
+  success: boolean;
+  /** Path to config.toml */
+  configPath: string;
+  /** Path to auth.json */
+  authPath: string;
+  /** config.toml content with sensitive values masked */
+  configToml: string | null;
+  /** auth.json content with API keys masked */
+  authJson: string | null;
+  /** Error messages if any files could not be read */
+  errors?: string[];
+}
+
+/**
+ * Gemini config preview response
+ */
+export interface GeminiConfigPreviewResponse {
+  /** Whether preview was successful */
+  success: boolean;
+  /** Path to settings.json */
+  settingsPath: string;
+  /** settings.json content with sensitive values masked */
+  settingsJson: string | null;
+  /** Error messages if file could not be read */
+  errors?: string[];
+}
+
+/**
+ * Fetch Codex config files preview (config.toml and auth.json)
+ */
+export async function fetchCodexConfigPreview(): Promise<CodexConfigPreviewResponse> {
+  return fetchApi('/api/cli/settings/codex/preview');
+}
+
+/**
+ * Fetch Gemini settings file preview (settings.json)
+ */
+export async function fetchGeminiConfigPreview(): Promise<GeminiConfigPreviewResponse> {
+  return fetchApi('/api/cli/settings/gemini/preview');
+}
+
 // ========== Orchestrator Execution Monitoring API ==========
 
 /**