feat(cliproxy): set WRITABLE_PATH for log storage in ~/.ccs/cliproxy/

- Add getCliproxyWritablePath() helper function
- Set WRITABLE_PATH env var when spawning CLIProxy in both executors
- Logs will now be stored in ~/.ccs/cliproxy/logs/ instead of CWD
- Enables error log viewer to find logs in predictable location

Note: CLIProxyAPI still has hardcoded MaxBackups=0 (unlimited).
Log rotation should be addressed in CLIProxyAPI upstream.

src/cliproxy/cliproxy-executor.ts

@@ -24,6 +24,7 @@ import {
   getProviderConfig,
   ensureProviderSettings,
   CLIPROXY_DEFAULT_PORT,
+  getCliproxyWritablePath,
 } from './config-generator';
 import { isAuthenticated } from './auth-handler';
 import { CLIProxyProvider, ExecutorConfig } from './types';
@@ -369,6 +370,10 @@ export async function execClaudeWithCLIProxy(
     proxy = spawn(binaryPath, proxyArgs, {
       stdio: ['ignore', 'ignore', 'ignore'],
       detached: true, // Persist after parent terminal closes
+      env: {
+        ...process.env,
+        WRITABLE_PATH: getCliproxyWritablePath(), // Logs stored in ~/.ccs/cliproxy/logs/
+      },
     });
 
     // Unref so parent process can exit independently

src/cliproxy/config-generator.ts

@@ -30,6 +30,15 @@ export const CCS_INTERNAL_API_KEY = 'ccs-internal-managed';
 /** Simple secret key for Control Panel login (user-facing) */
 export const CCS_CONTROL_PANEL_SECRET = 'ccs';
 
+/**
+ * Get CLIProxy writable directory for logs and runtime files.
+ * This directory is set as WRITABLE_PATH env var when spawning CLIProxy.
+ * Logs will be stored in ~/.ccs/cliproxy/logs/
+ */
+export function getCliproxyWritablePath(): string {
+  return path.join(getCcsDir(), 'cliproxy');
+}
+
 /**
  * Config version - bump when config format changes to trigger regeneration
  * v1: Initial config (port, auth-dir, api-keys only)

src/cliproxy/service-manager.ts

@@ -19,6 +19,7 @@ import {
   regenerateConfig,
   configNeedsRegeneration,
   CLIPROXY_DEFAULT_PORT,
+  getCliproxyWritablePath,
 } from './config-generator';
 import { isCliproxyRunning } from './stats-fetcher';
 
@@ -171,6 +172,10 @@ export async function ensureCliproxyService(
   proxyProcess = spawn(binaryPath, proxyArgs, {
     stdio: ['ignore', verbose ? 'pipe' : 'ignore', verbose ? 'pipe' : 'ignore'],
     detached: true, // Allow process to run independently
+    env: {
+      ...process.env,
+      WRITABLE_PATH: getCliproxyWritablePath(), // Logs stored in ~/.ccs/cliproxy/logs/
+    },
   });
 
   // Forward output in verbose mode