Fix AttributeError in docstring meta init and improve test isolation across shell tests

[Copilot]

command_class.docstring.meta was only initialized inside if args or kwargs:, causing an AttributeError when a command had examples but no args/kwargs. Several shell tests also shared the same command name "single command", risking cross-test registry pollution with no cleanup.

test_man_utils.py

• Initialize docstring.meta = [] unconditionally before the conditional append, fixing the AttributeError path

# Before
if args or kwargs:
    command_class.docstring.meta = [DocstringMeta(["arg"], "")]
for label, description in examples.items():
    command_class.docstring.meta.append(...)  # AttributeError if no args/kwargs

# After
command_class.docstring.meta = []
if args or kwargs:
    command_class.docstring.meta.append(DocstringMeta(["arg"], ""))
for label, description in examples.items():
    command_class.docstring.meta.append(...)

test_shell.py

• Assign unique command names per test ("single command dash c", "single command non repl", "single command one shot", "single command sys argv") to eliminate inter-test interference
• Rename inner single_command functions to single_cmd to avoid shadowing the outer single_command kwarg in relax()
• Add try/finally cleanup in test_run_with_dash_c with pre/post assertions on COMMAND_REGISTRY
• Replace monkeypatch.setattr(bc, "debug", lambda: debug_called.__setitem__(0, True)) with a named mock_debug() closure
• Use monkeypatch.setitem(recline.commands.COMMAND_REGISTRY, ...) in test_run_one_command_command_cancelled so pytest handles teardown automatically

Original prompt

Please apply the following diffs and create a pull request.
Once the PR is ready, give it a title based on the messages of the fixes being applied.

[{"message":"The condition `if args or kwargs:` initializes `command_class.docstring.meta` only when there are args or kwargs, but line 96 always attempts to append to `command_class.docstring.meta` regardless of whether it was initialized. If there are no args or kwargs but there are examples, this will fail with an AttributeError. Consider initializing `command_class.docstring.meta` unconditionally or adding a check before appending.","fixFiles":[{"filePath":"tests/test_commands/test_man_utils.py","diff":"diff --git a/tests/test_commands/test_man_utils.py b/tests/test_commands/test_man_utils.py\n--- a/tests/test_commands/test_man_utils.py\n+++ b/tests/test_commands/test_man_utils.py\n@@ -90,8 +90,9 @@\n         Parameter(arg, Parameter.KEYWORD_ONLY, default=val)\n         for arg, val in kwargs.items()\n     ]\n+    command_class.docstring.meta = []\n     if args or kwargs:\n-        command_class.docstring.meta = [DocstringMeta([\"arg\"], \"\")]\n+        command_class.docstring.meta.append(DocstringMeta([\"arg\"], \"\"))\n     for label, description in examples.items():\n         command_class.docstring.meta.append(\n             DocstringMeta([\"examples\", label], description)\n"}]},{"message":"The test does not verify cleanup of the command from the registry after execution. Consider adding assertions to ensure that command registration doesn't leak across tests.","fixFiles":[{"filePath":"tests/test_repl/test_shell.py","diff":"diff --git a/tests/test_repl/test_shell.py b/tests/test_repl/test_shell.py\n--- a/tests/test_repl/test_shell.py\n+++ b/tests/test_repl/test_shell.py\n@@ -108,13 +108,24 @@\n def test_run_with_dash_c():\n     \"\"\"Verify only a single command is run when -c is passed in\"\"\"\n \n-    @recline.command(name=\"single command\")\n+    command_name = \"single command\"\n+    preexisting = command_name in recline.commands.COMMANDS\n+\n+    @recline.command(name=command_name)\n     def single_command():\n         return 73\n \n-    assert shell.relax(argv=[\"ut_program\", \"-c\", \"single\", \"command\"]) == 73\n+    try:\n+        assert shell.relax(argv=[\"ut_program\", \"-c\", \"single\", \"command\"]) == 73\n+        assert command_name in recline.commands.COMMANDS\n+    finally:\n+        if not preexisting:\n+            recline.commands.COMMANDS.pop(command_name, None)\n \n+    if not preexisting:\n+        assert command_name not in recline.commands.COMMANDS\n \n+\n def test_run_non_repl():\n     \"\"\"Verify that if a program is not trying to be a repl, then we will parse\n     a command from the input and exit\n"}]},{"message":"The function name 'single_command' shadows the outer scope variable (the decorator parameter). Consider renaming the function to 'single_cmd' or 'cmd_single' to avoid confusion.","fixFiles":[{"filePath":"tests/test_repl/test_shell.py","diff":"diff --git a/tests/test_repl/test_shell.py b/tests/test_repl/test_shell.py\n--- a/tests/test_repl/test_shell.py\n+++ b/tests/test_repl/test_shell.py\n@@ -109,7 +109,7 @@\n     \"\"\"Verify only a single command is run when -c is passed in\"\"\"\n \n     @recline.command(name=\"single command\")\n-    def single_command():\n+    def single_cmd():\n         return 73\n \n     assert shell.relax(argv=[\"ut_program\", \"-c\", \"single\", \"command\"]) == 73\n@@ -121,7 +121,7 @@\n     \"\"\"\n \n     @recline.command(name=\"single command\")\n-    def single_command():\n+    def single_cmd():\n         return 73\n \n     assert shell.relax(argv=[\"ut_program\", \"single\", \"command\"], repl_mode=False) == 73\n@@ -133,7 +133,7 @@\n     \"\"\"\n \n     @recline.command(name=\"single command\")\n-    def single_command():\n+    def single_cmd():\n         return 73\n \n     assert shell.relax(argv=[\"ut_program\"], single_command=\"single command\") == 73\n"}]},{"message":"The function name 'single_command' is reused across multiple tests (lines 113, 123, 136, 148). This could lead to test interference if the command registry is not properly cleaned between tests. Consider using unique names for each test or ensure proper cleanup.","fixFiles":[{"filePath":"tests/test_repl/test_shell.py","diff":"diff --git a/tests/test_repl/test_shell.py b/tests/test_repl/test_shell.py\n--- a/tests/test_repl/test_shell.py\n+++ b/tests/test_repl/test_shell.py\n@@ -108,11 +108,11 @@\n def test_run_with_dash_c():\n     \"\"\"Verify only a single command is run when -c is passed in\"\"\"\n \n-    @recline.command(name=\"single command\")\n+    @recline.command(name=\"single command dash c\")\n     def single_command():\n         return 73\n \n-    assert shell.relax(argv=[\"ut_program\", \"-c\", \"single\", \"command\"]) == 73\n+    assert shell.relax(argv=[\"ut_program\", \"-c\", \"single\", \"command\", \"dash\", \"c\"]) == 73\n \n \n def test_run_non_repl():\n@@ -120,11 +117,...