feat: enable persistent shell by default for SSH, add config option

SSH persistent shell now defaults to true — non-local backends benefit
most from state persistence across execute() calls. Local backend
remains opt-in via TERMINAL_LOCAL_PERSISTENT env var.

New config.yaml option: terminal.persistent_shell (default: true)
Controls the default for non-local backends. Users can disable with:
  hermes config set terminal.persistent_shell false

Precedence: per-backend env var > TERMINAL_PERSISTENT_SHELL > default.

Wired through cli.py, gateway/run.py, and hermes_cli/config.py so the
config.yaml value reaches terminal_tool via env var bridge.

cli.py

@@ -328,6 +328,8 @@ def load_cli_config() -> Dict[str, Any]:
         "container_persistent": "TERMINAL_CONTAINER_PERSISTENT",
         "docker_volumes": "TERMINAL_DOCKER_VOLUMES",
         "sandbox_dir": "TERMINAL_SANDBOX_DIR",
+        # Persistent shell (non-local backends)
+        "persistent_shell": "TERMINAL_PERSISTENT_SHELL",
         # Sudo support (works with all backends)
         "sudo_password": "SUDO_PASSWORD",
     }

gateway/run.py

@@ -77,6 +77,7 @@ if _config_path.exists():
                 "container_persistent": "TERMINAL_CONTAINER_PERSISTENT",
                 "docker_volumes": "TERMINAL_DOCKER_VOLUMES",
                 "sandbox_dir": "TERMINAL_SANDBOX_DIR",
+                "persistent_shell": "TERMINAL_PERSISTENT_SHELL",
             }
             for _cfg_key, _env_var in _terminal_env_map.items():
                 if _cfg_key in _terminal_cfg:

hermes_cli/config.py

@@ -118,6 +118,11 @@ DEFAULT_CONFIG = {
         # Each entry is "host_path:container_path" (standard Docker -v syntax).
         # Example: ["/home/user/projects:/workspace/projects", "/data:/data"]
         "docker_volumes": [],
+        # Persistent shell — keep a long-lived bash shell across execute() calls
+        # so cwd/env vars/shell variables survive between commands.
+        # Enabled by default for non-local backends (SSH); local is always opt-in
+        # via TERMINAL_LOCAL_PERSISTENT env var.
+        "persistent_shell": True,
     },
     
     "browser": {
@@ -1391,6 +1396,7 @@ def set_config_value(key: str, value: str):
         "terminal.cwd": "TERMINAL_CWD",
         "terminal.timeout": "TERMINAL_TIMEOUT",
         "terminal.sandbox_dir": "TERMINAL_SANDBOX_DIR",
+        "terminal.persistent_shell": "TERMINAL_PERSISTENT_SHELL",
     }
     if key in _config_to_env_sync:
         save_env_value(_config_to_env_sync[key], str(value))

tests/tools/test_ssh_environment.py

@@ -67,16 +67,31 @@ class TestBuildSSHCommand:
 
 
 class TestTerminalToolConfig:
-    def test_ssh_persistent_default_false(self, monkeypatch):
+    def test_ssh_persistent_default_true(self, monkeypatch):
+        """SSH persistent defaults to True (via TERMINAL_PERSISTENT_SHELL)."""
         monkeypatch.delenv("TERMINAL_SSH_PERSISTENT", raising=False)
+        monkeypatch.delenv("TERMINAL_PERSISTENT_SHELL", raising=False)
+        from tools.terminal_tool import _get_env_config
+        assert _get_env_config()["ssh_persistent"] is True
+
+    def test_ssh_persistent_explicit_false(self, monkeypatch):
+        """Per-backend env var overrides the global default."""
+        monkeypatch.setenv("TERMINAL_SSH_PERSISTENT", "false")
         from tools.terminal_tool import _get_env_config
         assert _get_env_config()["ssh_persistent"] is False
 
-    def test_ssh_persistent_true(self, monkeypatch):
+    def test_ssh_persistent_explicit_true(self, monkeypatch):
         monkeypatch.setenv("TERMINAL_SSH_PERSISTENT", "true")
         from tools.terminal_tool import _get_env_config
         assert _get_env_config()["ssh_persistent"] is True
 
+    def test_ssh_persistent_respects_config(self, monkeypatch):
+        """TERMINAL_PERSISTENT_SHELL=false disables SSH persistent by default."""
+        monkeypatch.delenv("TERMINAL_SSH_PERSISTENT", raising=False)
+        monkeypatch.setenv("TERMINAL_PERSISTENT_SHELL", "false")
+        from tools.terminal_tool import _get_env_config
+        assert _get_env_config()["ssh_persistent"] is False
+
 
 def _setup_ssh_env(monkeypatch, persistent: bool):
     monkeypatch.setenv("TERMINAL_ENV", "ssh")

tools/terminal_tool.py

@@ -505,7 +505,13 @@ def _get_env_config() -> Dict[str, Any]:
         "ssh_user": os.getenv("TERMINAL_SSH_USER", ""),
         "ssh_port": _parse_env_var("TERMINAL_SSH_PORT", "22"),
         "ssh_key": os.getenv("TERMINAL_SSH_KEY", ""),
-        "ssh_persistent": os.getenv("TERMINAL_SSH_PERSISTENT", "false").lower() in ("true", "1", "yes"),
+        # Persistent shell: SSH defaults to the config-level persistent_shell
+        # setting (true by default for non-local backends); local is always opt-in.
+        # Per-backend env vars override if explicitly set.
+        "ssh_persistent": os.getenv(
+            "TERMINAL_SSH_PERSISTENT",
+            os.getenv("TERMINAL_PERSISTENT_SHELL", "true"),
+        ).lower() in ("true", "1", "yes"),
         "local_persistent": os.getenv("TERMINAL_LOCAL_PERSISTENT", "false").lower() in ("true", "1", "yes"),
         # Container resource config (applies to docker, singularity, modal, daytona -- ignored for local/ssh)
         "container_cpu": _parse_env_var("TERMINAL_CONTAINER_CPU", "1", float, "number"),