"""Smart parser that attempts to extract structured data from a string using multiple approaches.

Handles:
1. Pure JSON objects
2. JSON embedded in text
3. Key-value pairs in formats like:
   - key="value"
   - key=value
   - Key: "value"
   - key: value
4. Plain text (stored under 'message' key)

Args:
    text (str): Input text to parse

Returns:
    dict: Parsed data or {'message': text} if no structure found. The parsed data includes key-value pairs extracted from the text, with keys converted to lowercase. Any remaining text that does not match the structured formats is stored under the 'message' key.
"""
You should write code starting with:
import re
import json

def smart_parse(text: str) -> dict:
    # TODO: Implement this function
    pass

