XML special characters in setting values break production definition generation

[reet0512]

• iris kit details: 'any — issue is in the Python code generator'
• operating system: 'any'
• python version: 'any'
• error message: 'IRIS compilation error on the generated production class due to invalid XML'

Steps to Reproduce:

1. Define a ServiceItem/ProcessItem/OperationItem with a setting value containing &, <, >, or "
2. Run the code generator

Minimal Example

from intersystems_pyprod import Production, ServiceItem

class MyProduction(Production):
    services = [
        ServiceItem(
            "MyService",
            "EnsLib.File.PassthroughService",
            adapter_settings={
                "FilePath": "/data/input&output",
            },
        )
    ]

Expected Behaviour

The value is XML-escaped (&) in the generated <Setting> element.

Actual Behaviour

Raw & is interpolated, producing invalid XML that fails to compile on IRIS side.

Additional Information

Root cause: _production_definition.py:_create_item_target_settings uses f-string
interpolation with no escaping. Same applies to item attributes (name, comment, schedule)
in _create_production_item.

Related to #6 (same category of unescaped interpolation into generated code).