fix(cli): stop leaking API keys to CLI app subprocesses

Installed CLI apps were started with os.environ.copy(), so provider keys
from the parent process were visible to untrusted binaries. Use a minimal
allowlist env matching the shell tool.

Fixes #4783

nanobot/apps/cli/service.py

@@ -1019,7 +1019,7 @@ class CliAppManager:
             "PYTHONUNBUFFERED": "1",
         }
 
-        def _run_argv(self, argv: list[str], *, timeout: int) -> subprocess.CompletedProcess[str]:
+    def _run_argv(self, argv: list[str], *, timeout: int) -> subprocess.CompletedProcess[str]:
         command = subprocess.list2cmdline(argv)
         logger.info("CLI Apps: running {}", command)
         result = subprocess.run(