fix(data_import): use lazy imports to prevent excel-to-sql load errors

Replace module-level imports with lazy imports using __getattr__.
This prevents excel-to-sql from being imported at application startup,
which causes ImportError in the compiled Windows executable when the
auto_pilot module is bundled but not properly initialized.

The lazy import ensures excel-to-sql is only loaded when actually
needed (e.g., during data import operations), not during module
initialization or GUI startup.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: codewizdave

src/wareflow_analysis/data_import/__init__.py

@@ -1,9 +1,34 @@
 """Data import module for wareflow-analysis.
 
 This module provides data import functionality using excel-to-sql Auto-Pilot Mode.
+
+Note: Uses lazy imports to avoid triggering excel-to-sql imports at module load time.
+This prevents import errors when the module is imported but not actively used.
 """
 
-from wareflow_analysis.data_import.autopilot import generate_autopilot_config
-from wareflow_analysis.data_import.importer import run_import
+# Lazy imports - these are only imported when actually used
+# This prevents issues with excel-to-sql dependency loading
 
 __all__ = ["generate_autopilot_config", "run_import"]
+
+
+def __getattr__(name: str):
+    """Lazy import attributes only when accessed.
+
+    Args:
+        name: Attribute name being accessed
+
+    Returns:
+        The requested attribute
+
+    Raises:
+        AttributeError: If attribute doesn't exist
+    """
+    if name == "generate_autopilot_config":
+        from wareflow_analysis.data_import.autopilot import generate_autopilot_config
+        return generate_autopilot_config
+    elif name == "run_import":
+        from wareflow_analysis.data_import.importer import run_import
+        return run_import
+    else:
+        raise AttributeError(f"module '{__name__}' has no attribute '{name}'")