🧪 [AmbientBiota] Add missing error tests for try-finally blocks

[marko1olo]

🎯 What: The testing gap addressed
The AmbientBiotaDirector processes continuous loops via Tick and SlowTick. Both methods utilize a try-finally pattern to guarantee that if an exception breaks the inner execution, the pinned job buffers (ReleaseBiotaJobBufferPins()) are successfully unpinned so memory isn't permanently locked. This pattern was missing test coverage.

📊 Coverage: What scenarios are now tested
Added Tick_ExceptionInTryBlock_EnsuresJobBufferPinsAreReleased and SlowTick_ExceptionInTryBlock_EnsuresJobBufferPinsAreReleased using NSubstitute to intentionally throw InvalidOperationException and verify cleanup.

✨ Result: The improvement in test coverage
Robustness is properly tested and verified. If code changes in the future inadvertently disable this cleanup block, these unit tests will catch the regression.

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PR created automatically by Jules for task 1801304102273012162 started by @marko1olo

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