feat: add complex root finding and dynamic CUDA shared memory optimization

Major update extending the library to solve for complex roots and optimizing GPU performance using Shared Memory.

Complex Number Support:
- Implemented `_solve_complex_cuda` and `_solve_complex_numpy` to find roots in the complex plane.
- Added specialized CUDA kernels (`_FITNESS_KERNEL_COMPLEX`, `_FITNESS_KERNEL_COMPLEX_DYNAMIC`) handling complex arithmetic (multiplication/addition) directly on the GPU.
- Updated `Function` class and `set_coeffs` to handle `np.complex128` data types.
- Updated `quadratic_solve` to return complex roots using `cmath`.

CUDA Performance & Optimization:
- Implemented Dynamic Shared Memory kernels (`extern __shared__`) to cache polynomial coefficients on the GPU block, significantly reducing global memory latency.
- Added intelligent fallback logic: The solver checks `MaxSharedMemoryPerBlock`. If the polynomial is too large for Shared Memory, it falls back to the standard Global Memory kernel to prevent crashes.
- Split complex coefficients into separate Real and Imaginary arrays for CUDA kernel efficiency.

Polynomial Logic:
- Added `_strip_leading_zeros` helper to ensure polynomial degree is correctly maintained after arithmetic operations (e.g., preventing `0x^2 + x` from being treated as degree 2).
- Updated `__init__` to allow direct coefficient injection.

GA Algorithm:
- Updated crossover logic to support 2D search space (Real + Imaginary) for complex solutions.
- Refined fitness function to explicitly handle `isinf`/`isnan` for numerical stability.

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 # --- Core Metadata ---
 name = "polysolve"
-version = "0.6.3"
+version = "0.7.0"
 authors = [
   { name="Jonathan Rampersad", email="jonathan@jono-rams.work" },
 ]