fix(list): 非 TTY フォールバック判定に stdout.isatty() を追加

`devbase list | cat` や `devbase list > out.txt` のように stdout だけが
非 TTY のケースでも対話選択が起動してしまう問題を修正。stdin / stdout の
いずれかが非 TTY なら確実に一覧表示へフォールバックするよう判定を拡張した。
stdout 非 TTY フォールバックのテストも追加。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: takemi-ohama

lib/devbase/commands/project.py

@@ -177,7 +177,9 @@ def cmd_project_list(devbase_root: Path, args) -> int:
 
     # 対話選択はデフォルト ON。ただし非 TTY (パイプ / CI / リダイレクト) では
     # input() が EOFError になり実用にならないため、自動的に一覧表示へフォールバック。
-    if getattr(args, "interactive", True) and sys.stdin.isatty():
+    # stdin / stdout のいずれかが非 TTY (`devbase list | cat`, `> out.txt` 等) なら
+    # 対話プロンプトが表示できない / 読めないため、確実に一覧表示へフォールバックする。
+    if getattr(args, "interactive", True) and sys.stdin.isatty() and sys.stdout.isatty():
         return _interactive_select_and_up(rows)
 
     _print_table(rows)

tests/cli/test_project_list.py

@@ -246,6 +246,32 @@ def test_cmd_project_list_non_tty_falls_back_to_table(tmp_path, monkeypatch, cap
     assert "alpha-proj" in out
 
 
+def test_cmd_project_list_stdout_non_tty_falls_back_to_table(tmp_path, monkeypatch, capsys):
+    """stdin が TTY でも stdout が非 TTY (`devbase list | cat` / `> out.txt`) なら
+    対話起動せず一覧表示へフォールバックする。"""
+    from devbase.commands import project as project_mod
+    from devbase.commands import status as status_mod
+    from devbase.commands import container as container_mod
+
+    _make_plugin_project(tmp_path, "repos/o--r/alpha", "alpha-proj")
+    _link_project(tmp_path, "alpha-proj", "repos/o--r/alpha", "alpha-proj")
+    monkeypatch.setattr(status_mod, "_container_status_for",
+                        lambda entry: {"name": entry.name, "status": "stopped", "count": 0})
+    monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: False)
+
+    called = []
+    monkeypatch.setattr(container_mod, "cmd_project", lambda args: called.append(1) or 0)
+
+    args = types.SimpleNamespace(interactive=True)
+    rc = project_mod.cmd_project_list(tmp_path, args)
+    out = capsys.readouterr().out
+
+    assert rc == 0
+    assert called == [], "stdout 非 TTY では対話起動しない"
+    assert "alpha-proj" in out
+
+
 # ---------------------------------------------------------------------------
 # cmd_project_list: --interactive
 # ---------------------------------------------------------------------------
@@ -263,6 +289,7 @@ def test_cmd_project_list_interactive_selects_and_ups(tmp_path, monkeypatch):
 
     # 対話選択は TTY 環境でのみ起動するため isatty を True に固定する。
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     # 番号 "2" を選択 (sorted: alpha-proj=1, beta-proj=2)
     monkeypatch.setattr("builtins.input", lambda *a, **k: "2")
 
@@ -288,6 +315,7 @@ def test_cmd_project_list_interactive_empty_input_aborts(tmp_path, monkeypatch):
     _link_project(tmp_path, "alpha-proj", "repos/o--r/alpha", "alpha-proj")
     monkeypatch.setattr(status_mod, "_container_status_for", lambda entry: None)
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     monkeypatch.setattr("builtins.input", lambda *a, **k: "")
 
     called = []
@@ -313,6 +341,7 @@ def raise_eof(*a, **k):
         raise EOFError
 
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     monkeypatch.setattr("builtins.input", raise_eof)
     called = []
     monkeypatch.setattr(container_mod, "cmd_project", lambda args: called.append(1) or 0)
@@ -337,6 +366,7 @@ def raise_interrupt(*a, **k):
         raise KeyboardInterrupt
 
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     monkeypatch.setattr("builtins.input", raise_interrupt)
     called = []
     monkeypatch.setattr(container_mod, "cmd_project", lambda args: called.append(1) or 0)
@@ -358,6 +388,7 @@ def test_cmd_project_list_interactive_out_of_range_reprompts(tmp_path, monkeypat
     monkeypatch.setattr(status_mod, "_container_status_for", lambda entry: None)
 
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     # "99" (範囲外) → "1" (有効) の順に入力 → 再入力後に up が起動する
     inputs = iter(["99", "1"])
     monkeypatch.setattr("builtins.input", lambda *a, **k: next(inputs))
@@ -382,6 +413,7 @@ def test_cmd_project_list_interactive_non_numeric_reprompts(tmp_path, monkeypatc
     monkeypatch.setattr(status_mod, "_container_status_for", lambda entry: None)
 
     monkeypatch.setattr(project_mod.sys.stdin, "isatty", lambda: True)
+    monkeypatch.setattr(project_mod.sys.stdout, "isatty", lambda: True)
     # "abc" (数値以外) → "1" (有効)
     inputs = iter(["abc", "1"])
     monkeypatch.setattr("builtins.input", lambda *a, **k: next(inputs))