Fix: Add algorithm name validation in OsipiBase.osipi_initiate_algorithm()

[Devguru-codes]

This PR fixes the issue where OsipiBase crashes with a confusing ModuleNotFoundError or AttributeError when initialized with a misspelled or invalid algorithm name. The dynamic class loader in osipi_initiate_algorithm() previously performed zero validation before calling importlib.import_module(), causing raw Python import errors to surface to the user.

Changes Made

src/wrappers/OsipiBase.py

1. Algorithm name validation: Before attempting the dynamic import, the method now scans the src/standardized/ directory using pathlib.glob("*.py") to build a set of valid algorithm names at runtime. This approach is always in sync with the actual codebase — no hardcoded list needed.

2. Clear ValueError: If the requested algorithm is not found, a ValueError is raised listing all available algorithms alphabetically, making typos easy to spot.

3. Secondary safety net: The importlib.import_module() and getattr() calls are now wrapped in explicit try/except blocks with descriptive error messages:

   • ImportError — if the file exists but fails to import (e.g., syntax error in the module).
   • AttributeError — if the module loads but doesn't contain the expected class name.

4. Updated docstring: Added Raises section documenting the ValueError.

tests/IVIMmodels/unit_tests/test_ivim_fit.py

Added test_invalid_algorithm_name() regression test with 3 sub-checks:

1. A typo ("IAR_LU_biepx") raises ValueError with "not found" in the message.
2. A completely fake name ("totally_fake_algorithm") raises ValueError that includes "Available algorithms are:" and lists known algorithms like IAR_LU_biexp and PV_MUMC_biexp.
3. A valid algorithm ("IAR_LU_biexp") still initializes successfully without errors (no false positives).

Testing & Validation

$ python -m pytest tests/IVIMmodels/unit_tests/test_ivim_fit.py::test_invalid_algorithm_name -v
tests/.../test_ivim_fit.py::test_invalid_algorithm_name PASSED [100%]
1 passed in 1.81s

$ python -m pytest tests/IVIMmodels/unit_tests/test_ivim_fit.py::test_default_bounds_and_initial_guesses -v
22 passed, 5 skipped in 2.24s

• New test passes — invalid names correctly raise ValueError
• Existing tests unaffected — all 22 algorithm-loading tests still pass (5 MATLAB/DL skipped as expected)

fixes #159

[IvanARashid]

Looks good, just one more adjustment so that we stay consistent.

[Devguru-codes]

Looks good, just one more adjustment so that we stay consistent.

I have implemented the change sir. Thank you.

[oliverchampion]

Looks good to me. If Ivan agrees we can merge

[IvanARashid]

Looks good now, thanks!