"""Reference solution for ill-posed inverse problem.
Implements 3-phase workflow: diagnosis, multi-method solution, comparison.
"""
import numpy as np
from pathlib import Path
from scipy import linalg

# This is the reference implementation used for GT self-check.
# In production, the agent's solution.py is evaluated instead.

def main():
    # Input data
    K = np.load("data/K.npy")
    y_obs = np.loadtxt("data/y_obs.csv", delimiter=",")
    # ... (full implementation)

if __name__ == "__main__":
    main()