Fix stale OAuth token causing silent failures in long-running proxy

src/subprocess/manager.ts

@@ -53,9 +53,17 @@ export class ClaudeSubprocess extends EventEmitter {
     return new Promise((resolve, reject) => {
       try {
         // Use spawn() for security - no shell interpretation
+        // Remove CLAUDE_CODE_OAUTH_TOKEN from the subprocess environment so the CLI
+        // reads fresh credentials from the OS keychain instead of using a potentially
+        // stale token snapshot inherited when this proxy process was started.
+        // Without this fix, the proxy silently fails with "out of extra usage" errors
+        // when the original token's usage window expires, even though the keychain
+        // token (auto-refreshed by Claude Desktop) remains valid.
+        const subprocessEnv = { ...process.env };
+        delete subprocessEnv.CLAUDE_CODE_OAUTH_TOKEN;
         this.process = spawn("claude", args, {
           cwd: options.cwd || process.cwd(),
-          env: { ...process.env },
+          env: subprocessEnv,
           stdio: ["pipe", "pipe", "pipe"],
         });