refactor(paths): use expandPath() consistently for cross-platform path handling

- variant-settings.ts: Use expandPath() in deleteSettingsFile()
- profile-writer.ts: Use expandPath() in removeApiProfileUnified()
- migration-manager.ts: Remove local expandPath(), import from helpers

All path expansion now uses the central expandPath() from utils/helpers.ts
which handles ~, ~\, ${VAR}, $VAR, and %VAR% on all platforms.

src/api/services/profile-writer.ts

@@ -6,6 +6,7 @@ import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
 import { getCcsDir, getConfigPath, loadConfig } from '../../utils/config-manager';
+import { expandPath } from '../../utils/helpers';
 import {
   loadOrCreateUnifiedConfig,
   saveUnifiedConfig,
@@ -144,9 +145,10 @@ function removeApiProfileUnified(name: string): void {
     throw new Error(`API profile not found: ${name}`);
   }
 
-  // Delete the settings file if it exists
+  // Delete the settings file if it exists.
+  // Uses expandPath() for cross-platform path handling.
   if (profile.settings) {
-    const settingsPath = profile.settings.replace(/^~/, os.homedir());
+    const settingsPath = expandPath(profile.settings);
     if (fs.existsSync(settingsPath)) {
       fs.unlinkSync(settingsPath);
     }

src/cliproxy/services/variant-settings.ts

@@ -10,6 +10,7 @@ import * as path from 'path';
 import * as os from 'os';
 import { CLIProxyProfileName } from '../../auth/profile-detector';
 import { getCcsDir } from '../../utils/config-manager';
+import { expandPath } from '../../utils/helpers';
 import { getClaudeEnvVars, CLIPROXY_DEFAULT_PORT } from '../config-generator';
 import { CLIProxyProvider } from '../types';
 
@@ -124,10 +125,11 @@ export function createSettingsFileUnified(
 }
 
 /**
- * Delete settings file if it exists
+ * Delete settings file if it exists.
+ * Uses expandPath() for cross-platform path handling.
  */
 export function deleteSettingsFile(settingsPath: string): boolean {
-  const resolvedPath = settingsPath.replace(/^~/, os.homedir());
+  const resolvedPath = expandPath(settingsPath);
   if (fs.existsSync(resolvedPath)) {
     fs.unlinkSync(resolvedPath);
     return true;

src/config/migration-manager.ts

@@ -15,6 +15,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import { getCcsDir } from '../utils/config-manager';
+import { expandPath } from '../utils/helpers';
 import type { ProfileConfig, AccountConfig, CLIProxyVariantConfig } from './unified-config-types';
 import { createEmptyUnifiedConfig } from './unified-config-types';
 import { saveUnifiedConfig, hasUnifiedConfig, loadUnifiedConfig } from './unified-config-loader';
@@ -311,13 +312,6 @@ function readJsonSafe(filePath: string): Record<string, unknown> | null {
   }
 }
 
-/**
- * Expand ~ to home directory in path.
- */
-function expandPath(p: string): string {
-  return p.replace(/^~/, process.env.HOME || '');
-}
-
 /**
  * Move file if it exists. Returns true if moved, false if source didn't exist.
  */