fix(tests): add BDD scenarios for rich/color formats with list data to restore coverage

Cover the list branches in _format_rich() and _format_color() that were
left untested, causing the coverage gate to drop below the 97% threshold.
Add two new @when steps (list+rich, list+color), two @then steps for list
panel assertions, and two new feature scenarios exercising those paths.

ISSUES CLOSED: #2921

features/cli_output_formats.feature

@@ -118,6 +118,16 @@ Feature: CLI output formats parity
     When I call format_output with a list and format plain
     Then the format result should contain separator lines
 
+  Scenario: Format output rich format handles list data
+    When I call format_output with a list and format rich
+    Then the format result should contain rich styled list output
+    And the format result should not be valid JSON
+
+  Scenario: Format output color format handles list data
+    When I call format_output with a list and format color
+    Then the format result should contain color styled list output
+    And the format result should not be plain text only
+
   Scenario: Serialize value handles enums and nested dicts
     When I call serialize_value with enum and nested data
     Then the serialized result should have string enum values

features/steps/cli_output_format_validation_steps.py

@@ -125,3 +125,27 @@ def step_format_result_not_plain_text(context: Context) -> None:
         f"format_output() with 'color' returned plain text — "
         f"expected ANSI-colored output, got: {result!r}"
     )
+
+
+@then("the format result should contain rich styled list output")
+def step_format_result_rich_list(context: Context) -> None:
+    """Assert rich format produces styled output for list data (panel per item)."""
+    result = context.format_result
+    assert "name" in result, f"Rich list output missing 'name': {result!r}"
+    has_ansi = "\033[" in result or "\x1b[" in result
+    has_item_panel = "Item 1" in result or "Item 2" in result
+    assert has_ansi or has_item_panel, (
+        f"Rich list output has no ANSI codes or item panels — got: {result!r}"
+    )
+
+
+@then("the format result should contain color styled list output")
+def step_format_result_color_list(context: Context) -> None:
+    """Assert color format produces styled output for list data (panel per item)."""
+    result = context.format_result
+    assert "name" in result, f"Color list output missing 'name': {result!r}"
+    has_ansi = "\033[" in result or "\x1b[" in result
+    has_item_panel = "Item 1" in result or "Item 2" in result
+    assert has_ansi or has_item_panel, (
+        f"Color list output has no ANSI codes or item panels — got: {result!r}"
+    )

features/steps/cli_output_formats_steps.py

@@ -456,6 +456,24 @@ def step_call_format_list_plain(context: Context) -> None:
     context.format_result = _capture_format_output(data, "plain")
 
 
+@when("I call format_output with a list and format rich")
+def step_call_format_list_rich(context: Context) -> None:
+    data = [
+        {"name": "a", "count": 1},
+        {"name": "b", "count": 2},
+    ]
+    context.format_result = _capture_format_output(data, "rich")
+
+
+@when("I call format_output with a list and format color")
+def step_call_format_list_color(context: Context) -> None:
+    data = [
+        {"name": "a", "count": 1},
+        {"name": "b", "count": 2},
+    ]
+    context.format_result = _capture_format_output(data, "color")
+
+
 @when("I call serialize_value with enum and nested data")
 def step_call_serialize_with_enum(context: Context) -> None:
     context.serialized = _serialize_value(