fix(completion): scan nested commands in unfinished braced args

Make the completion parser inspect nested command segments when an
unfinished braced argument is the active context, instead of treating the
entire braced body as opaque. This resolves cases where inner commands
(e.g. command substitutions) were ignored and improves suggestion
accuracy. Tests were added to cover nested commands inside braced
conditions and to ensure closed braced arguments do not change context.
Also add Linux-specific launch and task configurations to IDE settings
to simplify local extension development and debugging.

- Recursively scan inner context when a braced body is unfinished
- Add tests for nested commands and closed-brace behavior
- Add Linux launch/task entries for easier development

server/tests/python_tests/test_completion_context.py

@@ -204,6 +204,29 @@ def test_string_completion_handles_nested_commands_and_is_values():
     }
 
 
+def test_string_completion_inside_braced_conditions_and_bodies():
+    for prefix in ("if {", "while {", "proc example {} { if {"):
+        subcommands = _argument_completion_labels(prefix + "[string ")
+        assert subcommands is not None
+        assert {"compare", "equal", "is"} <= subcommands
+        assert _argument_completion_labels(prefix + "[string compare -") == {
+            "-length", "-nocase"
+        }
+        assert _argument_completion_labels(
+            prefix + "[string compare -nocase "
+        ) == {"-length"}
+
+
+def test_closed_braced_arguments_do_not_change_completion_context():
+    assert _argument_completion_labels("puts {[string compare }") is None
+    assert _argument_completion_labels(
+        "if {[string equal a b]} {string compare "
+    ) == {"-length", "-nocase"}
+    assert _argument_completion_labels(
+        "if {[string equal a b] && [string is integer "
+    ) == {"-failindex", "-strict"}
+
+
 def test_dict_array_namespace_file_and_info_subcommands():
     dict_items = _argument_completion_labels("dict ")
     assert dict_items is not None