fix(code): dedupe update/install log path output (#4553)

`dcode update` and install commands no longer print the same log path
twice.

---

Previously, update and install flows printed the log path once by itself
and then repeated it in the tail command:

```text
Update log: /tmp/deepagents-update.log
Tail progress: tail -f /tmp/deepagents-update.log
```

Now they print a single copy-pasteable command next to the log label:

```text
Update log: tail -f /tmp/deepagents-update.log
```

The same before/after applies to `Install log:` output for both extras
installs and arbitrary package installs. This keeps the path visible
while avoiding duplicate path output in the terminal.

Made by [Open
SWE](https://openswe.vercel.app/agents/91e79ce5-84aa-d27e-8cd5-dae63b3546c1)

---------

Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>

libs/code/deepagents_code/main.py

@@ -15,6 +15,7 @@ import importlib.util
 import json
 import logging
 import os
+import shlex
 import shutil
 import sys
 import traceback
@@ -40,6 +41,11 @@ _SANDBOX_DEFAULT_SENTINEL = "\x00default"
 """Marker stored by `--sandbox` with no value, resolved to `[sandboxes].default`."""
 
 
+def _tail_log_command(log_path: Path | str) -> str:
+    """Return a copy-pasteable command for following a log file."""
+    return f"tail -f {shlex.quote(str(log_path))}"
+
+
 def build_version_text() -> str:
     """Build the plain-text output for the `--version` CLI flag.
 
@@ -371,7 +377,7 @@ def _run_startup_auto_update(console: "Console") -> None:
             return
         log_path = create_update_log_path()
         console.print(
-            f"Progress: tail -f {log_path}",
+            f"Update log: {_tail_log_command(log_path)}",
             style="dim",
             highlight=False,
             markup=False,
@@ -2978,7 +2984,7 @@ def cli_main() -> None:
                     sys.exit(0)
                 log_path = create_update_log_path()
                 console.print(
-                    f"Update log: {log_path}\nTail progress: tail -f {log_path}",
+                    f"Update log: {_tail_log_command(log_path)}",
                     style="dim",
                     highlight=False,
                     markup=False,
@@ -3099,8 +3105,7 @@ def cli_main() -> None:
                 console.print(f"Installing package '{package}'...")
                 pkg_log_path = create_update_log_path()
                 console.print(
-                    f"Install log: {pkg_log_path}\n"
-                    f"Tail progress: tail -f {pkg_log_path}",
+                    f"Install log: {_tail_log_command(pkg_log_path)}",
                     style="dim",
                     highlight=False,
                     markup=False,
@@ -3210,7 +3215,7 @@ def cli_main() -> None:
                 console.print(f"Installing extra '{extra}'...")
                 log_path = create_update_log_path()
                 console.print(
-                    f"Install log: {log_path}\nTail progress: tail -f {log_path}",
+                    f"Install log: {_tail_log_command(log_path)}",
                     style="dim",
                     highlight=False,
                     markup=False,

libs/code/tests/unit_tests/test_main.py

@@ -132,6 +132,8 @@ class TestStartupAutoUpdate:
             _run_startup_auto_update(console)
 
         upgrade.assert_awaited_once()
+        printed = " ".join(str(c.args[0]) for c in console.print.call_args_list)
+        assert "tail -f /tmp/dcode-update.log" in printed
         restart.assert_called_once_with()
 
     def test_successful_update_skips_restart_when_shadowed(self) -> None:

libs/code/tests/unit_tests/test_main_args.py

@@ -1937,6 +1937,7 @@ class TestInstallExtraSubcommand:
         assert code == 0
         text = self._printed_text(console_mock)
         assert "Installed extra 'quickjs'" in text
+        assert "tail -f /tmp/deepagents-install.log" in text
 
     def test_failure_renders_log_path_and_manual_command(self) -> None:
         """A failed install surfaces both the log path and manual script command."""
@@ -2106,6 +2107,7 @@ class TestInstallPackageSubcommand:
         perform_mock.assert_awaited_once()
         text = self._printed_text(console_mock)
         assert "Installed package 'langchain-custom'" in text
+        assert "tail -f /tmp/deepagents-install.log" in text
 
     def test_package_non_interactive_without_yes_refuses(self) -> None:
         """Non-TTY stdin + no --yes must exit 2 without installing."""