fix(simplex): raise error instead of silent failure on max iterations

[Amruta-32]

Fixes silent failure in run_simplex().

Previously, when the maximum iteration limit was reached, the function returned an empty dictionary, making debugging impossible.

This change raises a ValueError instead, making the failure explicit and easier to debug.

Behavior change:

• Before: return {}
• After: raise ValueError with descriptive message

[algorithms-keeper]

Closing this pull request as invalid

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