[T-004] Add test suite for flux-optimizer

[SuperInstance]

Summary

• Added pytest test framework with conftest.py
• 30 tests covering OptResult, HALT truncate, NOP elimination, constant folding, strength reduction, redundant MOV elimination, combined passes, and bytecode output
• Uses pytest fixtures and parametrize
• All tests passing

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[beta-devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 4 additional findings.