Step 1: Simplifying the expression.
First, simplify \( (1+i)^2 \) and \( i(2i-1) \), then perform the division. After simplification, extract the imaginary part.
Step 2: Conclusion.
Thus, the imaginary part is \( \frac{-4}{5} \). Hence, the correct answer is option (D).
Final Answer:
\[
\boxed{\text{(D) } \frac{-4}{5}}
\]