refactor: Remove file-based license saving and loading methods.

license_manager.py

@@ -154,21 +154,4 @@ class LicenseManager:
         # Neither matches - could be both changed or completely invalid key
         return False, 'both_changed'
 
-    @staticmethod
-    def save_license(key):
-        try:
-            with open("license.dat", "w") as f:
-                f.write(key.strip())
-            return True
-        except:
-            return False
 
-    @staticmethod
-    def load_license():
-        if not os.path.exists("license.dat"):
-            return None
-        try:
-            with open("license.dat", "r") as f:
-                return f.read().strip()
-        except:
-            return None