Add debug logging throughout library

Added comprehensive debug logging to help users troubleshoot query
generation issues. Logs capture:

- Parameter style selection (set_style, render)
- Interpolation processing (expression, format_spec, value type)
- Literal validation steps
- Unsafe value usage
- Final rendered SQL and parameters

Users can enable debug logging with:
    logging.basicConfig(level=logging.DEBUG)

Author: nhumrich

tsql/__init__.py

@@ -1,18 +1,22 @@
 import re
 import string
 import datetime
+import logging
 from typing import NamedTuple, Tuple, Any, List, Dict, Iterable, Union, TYPE_CHECKING
 from string.templatelib import Template, Interpolation
 
 from tsql.styles import ParamStyle, QMARK
 
+logger = logging.getLogger(__name__)
+
 if TYPE_CHECKING:
     from tsql.query_builder import QueryBuilder
 
 default_style = QMARK
 
 def set_style(style: type[ParamStyle]):
     global default_style
+    logger.debug("Setting default parameter style to: %s", style.__name__)
     default_style = style
 
 
@@ -50,6 +54,7 @@ def __init__(self, template_string: Template):
     def render(self, style:ParamStyle = None) -> RenderedQuery:
         if style is None:
             style = default_style
+        logger.debug("Rendering query with style: %s", style.__name__)
         result = ''
 
         style_instance = style()
@@ -61,6 +66,8 @@ def render(self, style:ParamStyle = None) -> RenderedQuery:
             else:
                 result += part
 
+        logger.debug("Rendered SQL: %s", result)
+        logger.debug("Parameters (%d): %s", len(style_instance.params), style_instance.params)
         return RenderedQuery(result, style_instance.params)
 
 
@@ -114,11 +121,17 @@ def _sqlize(cls, val: Interpolation|Template|Any) -> list[str|Parameter]:
             if val.conversion:
                 value = formatter.convert_field(value, val.conversion)
 
+            logger.debug("Processing interpolation: expression=%r, format_spec=%r, value_type=%s",
+                        val.expression, val.format_spec, type(value).__name__)
+
             match val.format_spec, value:
                 case 'literal', str():
+                    logger.debug("Validating literal: %r", value)
                     cls._check_literal(value)
+                    logger.debug("Literal validated, inlining: %r", value)
                     return [value]
                 case 'unsafe', str():
+                    logger.debug("Using unsafe inline value: %r", value)
                     return [value]
                 case 'as_values', dict():
                     return as_values(value)._sql_parts