chore(tests): organize test scripts and beautify account creation email

- Moved scattered Python test scripts from root and 'admin/development/' to 'tests/'.
- Beautified the HTML email body for account creation links in 'app/methods/person_methods.py' with a modern responsive design.

tests/check_site_schema.py

@@ -0,0 +1,19 @@
+from app.db_sql import db
+from sqlalchemy import text
+
+def check_schema(name):
+    print(f"--- Schema for {name} ---")
+    try:
+        result = db.execute(text(f"DESCRIBE `{name}`"))
+        for row in result.fetchall():
+            print(f"  {row[0]} ({row[1]})")
+    except Exception as e:
+        print(f"  Error: {e}")
+    print("-" * 30)
+
+if __name__ == "__main__":
+    # Check tables
+    check_schema("site")
+    check_schema("site_domain")
+    # Check views used in CRUD V3
+    check_schema("v_site_domain")