Fix raise NotImplemented to raise NotImplementedError in wrap_llm_lora

[Mr-Neutr0n]

Summary

• NotImplemented is a built-in constant used for rich comparison methods, not an exception class. Raising it directly produces a confusing TypeError: exceptions must derive from BaseException instead of the expected NotImplementedError.
• This fixes the else branch in wrap_llm_lora() to properly raise NotImplementedError with a descriptive message indicating which LLM architecture is unsupported.

Before (broken):

raise NotImplemented
# TypeError: exceptions must derive from BaseException

After (fixed):

raise NotImplementedError(f'Unsupported architecture: {self.llm_arch_name}')
# NotImplementedError: Unsupported architecture: SomeModel

Test plan

• Verified that raise NotImplemented produces TypeError in Python
• Confirmed this is the only instance of this pattern in the codebase
• The fix follows the same pattern used elsewhere in the file (e.g., line 84)