Refactor Choices class init, fix inexact type coercion, quote-aware command splitting, and typo fixes

[Copilot]

Several independent bugs and code quality issues in choices.py and shell.py.

recline/arg_types/choices.py

• Remove __new__ for class attribute setup: available_choices and metavar were being set as class attributes inside __new__, which is unconventional. Replaced with explicit post-definition assignment after the inner _Choices class body.

• Fix inexact=True skipping data_type conversion: When inexact=True, the validate method returned the raw string without applying data_type, causing inconsistent return types. Now data_type(arg) is always applied; only the choice membership check is skipped.

# Before: inexact=True returned raw str regardless of data_type
if inexact:
    return arg  # bypasses data_type conversion

# After: validation skipped, type conversion always applied
if not inexact:
    current_choices = self.choices(eager=True)
    if arg not in current_choices:
        raise ReclineTypeError(...)
try:
    return data_type(arg)

recline/repl/shell.py

• Quote-aware command splitting: ;, &&, and || were split with str.split(), which breaks on operators inside quoted strings (e.g. echo "foo;bar" would produce two commands). Replaced with _split_unquoted(), a lightweight parser that respects single quotes, double quotes, and backslash escapes.

• Typo fixes: staring → starting, convienent → convenient, applicatinos → applications.

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":"Setting class attributes in `__new__` is unconventional and can lead to confusion. Class attributes are typically set in the class definition or `__init__`. Consider refactoring to use `__init__` or setting these as instance attributes to improve code clarity.","fixFiles":[{"filePath":"recline/arg_types/choices.py","diff":"diff --git a/recline/arg_types/choices.py b/recline/arg_types/choices.py\n--- a/recline/arg_types/choices.py\n+++ b/recline/arg_types/choices.py\n@@ -48,12 +48,9 @@\n         \"\"\"\n \n         class _Choices(Choices):\n-            def __new__(cls):\n-                instance = super().__new__(cls)\n-                cls.available_choices = available_choices\n-                if isinstance(available_choices, list):\n-                    cls.metavar = f\"<{'|'.join(available_choices)}>\"\n-                return instance\n+            available_choices = available_choices\n+            if isinstance(available_choices, list):\n+                metavar = f\"<{'|'.join(available_choices)}>\"\n \n             def validate(self, arg):\n                 if inexact:\n"}]},{"message":"When `inexact` is True, the function returns the raw argument without type conversion. This bypasses the `data_type` conversion on line 67, leading to inconsistent return types. The function should apply the `data_type` conversion before returning, even when validation is skipped.","fixFiles":[{"filePath":"recline/arg_types/choices.py","diff":"diff --git a/recline/arg_types/choices.py b/recline/arg_types/choices.py\n--- a/recline/arg_types/choices.py\n+++ b/recline/arg_types/choices.py\n@@ -56,13 +56,12 @@\n                 return instance\n \n             def validate(self, arg):\n-                if inexact:\n-                    return arg\n-                current_choices = self.choices(eager=True)\n-                if arg not in current_choices:\n-                    raise ReclineTypeError(\n-                        f\"\\\"{arg}\\\" must be one of {', '.join(current_choices)}.\"\n-                    )\n+                if not inexact:\n+                    current_choices = self.choices(eager=True)\n+                    if arg not in current_choices:\n+                        raise ReclineTypeError(\n+                            f\"\\\"{arg}\\\" must be one of {', '.join(current_choices)}.\"\n+                        )\n                 try:\n                     return data_type(arg)\n                 except Exception:  # pylint: disable=broad-except\n"}]},{"message":"Corrected spelling of 'staring' to 'starting'.","fixFiles":[{"filePath":"recline/repl/shell.py","diff":"diff --git a/recline/repl/shell.py b/recline/repl/shell.py\n--- a/recline/repl/shell.py\n+++ b/recline/repl/shell.py\n@@ -1,7 +1,7 @@\n \"\"\"\n Original © NetApp 2024\n \n-This is the main staring point for a recline application\n+This is the main starting point for a recline application\n \"\"\"\n \n import atexit\n"}]},{"message":"Corrected spelling of 'convienent' to 'convenient'.","fixFiles":[{"filePath":"recline/repl/shell.py","diff":"diff --git a/recline/repl/shell.py b/recline/repl/shell.py\n--- a/recline/repl/shell.py\n+++ b/recline/repl/shell.py\n@@ -56,7 +56,7 @@\n         repl_mode: By default, applications using recline expect to act as a REPL\n             environment where the user will run many commands. These applications\n             can still run a single command if the user passes a -c. But, it is\n-            convienent for some applications to act more like a traditional CLI\n+            convenient for some applications to act more like a traditional CLI\n             command without needing to pass -c. For those applicatinos, repl_mode\n             can be set to False.\n         single_command: This acts a bit like non-repl mode, except in this case\n"}]},{"message":"Corrected spelling of 'applicatinos' to 'applications'.","fixFiles":[{"filePath":"recline/repl/shell.py","diff":"diff --git a/recline/repl/shell.py b/recline/repl/shell.py\n--- a/recline/repl/shell.py\n+++ b/recline/repl/shell.py\n@@ -57,7 +57,7 @@\n             environment where the user will run many commands. These applications\n             can still run a single command if the user passes a -c. But, it is\n             convienent for some applications to act more like a traditional CLI\n-            command without needing to pass -c. For those applicatinos, repl_mode\n+            command without needing to pass -c. For those applications, repl_mode\n             can be set to False.\n         single_command: This acts a bit like non-repl mode, except in this case\n             the user doesn't have to pass any command name as an argument to the\n"}]},{"message":"The semicolon command separator splits naively without respecting quoted strings. A command like `echo \"foo;bar...