feat: add greet helper and document Sonar quality gate

Co-authored-by: Cursor <cursoragent@cursor.com>

hello.py

@@ -1,8 +1,13 @@
 """Hello world for TicketLab_MCP."""
 
 
+def greet(name: str = "TicketLab MCP") -> str:
+    """Return a greeting for the given name."""
+    return f"Hello, {name}!"
+
+
 def main() -> None:
-    print("Hello, TicketLab MCP!")
+    print(greet())
 
 
 if __name__ == "__main__":