feat(tera_factory): Implement hot reload example for Tera templates with Rhai

This commit adds a comprehensive hot reload example that demonstrates how to use the rhai_system for dynamic template rendering with Tera. Key improvements include:

- Refactor the example to use external script files instead of hardcoded Rhai code
- Implement proper module imports using the BasePathModuleResolver approach
- Fix template rendering by using keyword arguments in Tera function calls
- Add support for hot reloading both main and utility scripts
- Remove unnecessary output file generation to keep the example clean
- Fix compatibility issues with Rhai functions (avoiding to_string with parameters)

This example showcases how changes to Rhai scripts are automatically detected and applied to rendered templates without restarting the application, providing a smooth development experience.

tera_factory/examples/basic/scripts/math.rhai

@@ -0,0 +1,21 @@
+// Basic math functions for Tera templates
+
+// Add two numbers together
+fn sum(a, b) {
+    a + b
+}
+
+// Multiply two numbers
+fn multiply(a, b) {
+    a * b
+}
+
+// Format a number with a prefix and suffix
+fn format_number(number, prefix, suffix) {
+    prefix + number.to_string() + suffix
+}
+
+// Format a greeting with a name
+fn greet(name) {
+    "Hey, " + name + "!"
+}