fix(terminal): drop native ARGV0 for bun-pty via env -u

bun-pty merges the OS environ into PTY children, so deleting ARGV0 from the
JS env object alone left the AppImage path in the shell. Wrap Linux PTY
spawns with env -u ARGV0, clear native ARGV0 under Bun via libc unsetenv,
and always clear process.env even when no login-shell snapshot exists.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/web/server/lib/opencode/env-runtime.js

@@ -2,6 +2,7 @@ import { spawnSync } from 'node:child_process';
 import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
+import { clearAppImageArgv0FromProcessEnv } from '../inherited-env.js';
 import { mergePathValues } from './path-utils.js';
 
 export const createOpenCodeEnvRuntime = (deps) => {
@@ -227,6 +228,10 @@ export const createOpenCodeEnvRuntime = (deps) => {
   };
 
   const applyLoginShellEnvSnapshot = () => {
+    // Always clear AppImage ARGV0, even when no login-shell snapshot is available.
+    // Otherwise a leaked process.env.ARGV0 survives into later child spawns (#2588).
+    clearAppImageArgv0FromProcessEnv();
+
     const snapshot = getLoginShellEnvSnapshot();
     if (!snapshot) {
       return;
@@ -244,9 +249,6 @@ export const createOpenCodeEnvRuntime = (deps) => {
       process.env[key] = value;
     }
 
-    // AppImage ARGV0 must never remain on process.env (zsh rewrites argv[0]; #2588).
-    delete process.env.ARGV0;
-
     const currentPath = process.env.PATH || '';
     const shellPath = snapshot.PATH || '';
     if (!shellPath) {