refactor(cliproxy): extract shared auth utils and remove unused parameter

- Create auth-utils.ts with sanitizeEmail() and isTokenExpired()
- Remove duplicated functions from quota-fetcher-codex.ts
- Remove duplicated functions from quota-fetcher-gemini-cli.ts
- Remove unused _verbose parameter from displayAntigravityQuotaSection()
- Add descriptive comment to USER_AGENT constant

Addresses code review feedback on PR #395

src/cliproxy/auth-utils.ts

@@ -0,0 +1,27 @@
+/**
+ * Shared Authentication Utilities
+ *
+ * Common functions for OAuth token handling across quota fetchers.
+ */
+
+/**
+ * Sanitize email to match CLIProxyAPI auth file naming convention.
+ * Replaces @ and . with underscores for filesystem compatibility.
+ */
+export function sanitizeEmail(email: string): string {
+  return email.replace(/@/g, '_').replace(/\\./g, '_');
+}
+
+/**
+ * Check if token is expired based on the expired timestamp.
+ * Returns false if timestamp is missing or invalid (fail-open for quota display).
+ */
+export function isTokenExpired(expiredStr?: string): boolean {
+  if (!expiredStr) return false;
+  try {
+    const expiredDate = new Date(expiredStr);
+    return expiredDate.getTime() < Date.now();
+  } catch {
+    return false;
+  }
+}

src/cliproxy/quota-fetcher-codex.ts

@@ -9,12 +9,16 @@ import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { getAuthDir } from './config-generator';
 import { getProviderAccounts, getPausedDir } from './account-manager';
+import { sanitizeEmail, isTokenExpired } from './auth-utils';
 import type { CodexQuotaResult, CodexQuotaWindow } from './quota-types';
 
 /** ChatGPT backend API base URL */
 const CODEX_API_BASE = 'https://chatgpt.com/backend-api';
 
-/** User agent matching Codex CLI */
+/**
+ * User agent matching Codex CLI for API compatibility.
+ * Update when Codex CLI releases new versions to maintain compatibility.
+ */
 const USER_AGENT = 'codex_cli_rs/0.76.0 (Debian 13.0.0; x86_64) WindowsTerminal';
 
 /** Auth data extracted from Codex auth file */
@@ -51,26 +55,6 @@ interface CodexWindowData {
   resetAfterSeconds?: number | null;
 }
 
-/**
- * Sanitize email to match CLIProxyAPI auth file naming convention
- */
-function sanitizeEmail(email: string): string {
-  return email.replace(/@/g, '_').replace(/\./g, '_');
-}
-
-/**
- * Check if token is expired based on the expired timestamp
- */
-function isTokenExpired(expiredStr?: string): boolean {
-  if (!expiredStr) return false;
-  try {
-    const expiredDate = new Date(expiredStr);
-    return expiredDate.getTime() < Date.now();
-  } catch {
-    return false;
-  }
-}
-
 /**
  * Read auth data from Codex auth file
  */

src/cliproxy/quota-fetcher-gemini-cli.ts

@@ -9,6 +9,7 @@ import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { getAuthDir } from './config-generator';
 import { getProviderAccounts, getPausedDir } from './account-manager';
+import { sanitizeEmail, isTokenExpired } from './auth-utils';
 import type { GeminiCliQuotaResult, GeminiCliBucket } from './quota-types';
 
 /** Google Cloud Code API endpoints */
@@ -81,26 +82,6 @@ function resolveGeminiCliProjectId(accountField: string): string | null {
   return lastMatch;
 }
 
-/**
- * Sanitize email to match CLIProxyAPI auth file naming convention
- */
-function sanitizeEmail(email: string): string {
-  return email.replace(/@/g, '_').replace(/\./g, '_');
-}
-
-/**
- * Check if token is expired based on the expired timestamp
- */
-function isTokenExpired(expiredStr?: string): boolean {
-  if (!expiredStr) return false;
-  try {
-    const expiredDate = new Date(expiredStr);
-    return expiredDate.getTime() < Date.now();
-  } catch {
-    return false;
-  }
-}
-
 /**
  * Read auth data from Gemini CLI auth file
  */

src/commands/cliproxy-command.ts

@@ -1002,7 +1002,7 @@ async function handleQuotaStatus(
 
   // Display Antigravity section
   if (agyResults && agyResults.accounts.length > 0) {
-    displayAntigravityQuotaSection(agyResults, verbose);
+    displayAntigravityQuotaSection(agyResults);
   } else if (shouldFetch.agy) {
     console.log(subheader('Antigravity (0 accounts)'));
     console.log(info('No Antigravity accounts configured'));
@@ -1035,8 +1035,7 @@ async function handleQuotaStatus(
  * Display Antigravity quota section
  */
 function displayAntigravityQuotaSection(
-  quotaResult: Awaited<ReturnType<typeof fetchAllProviderQuotas>>,
-  _verbose: boolean
+  quotaResult: Awaited<ReturnType<typeof fetchAllProviderQuotas>>
 ): void {
   const provider: CLIProxyProvider = 'agy';
   const accounts = getProviderAccounts(provider);