[codex] rerun notebooks for 2.11.0

[daquinteroflex]

Rerun the affected notebooks and regenerate the optimized reflector GDS output.

Files updated:

• DirectionalCouplerSurrogate.ipynb
• GeneticAlgorithmReflector.ipynb
• MaxwellStressTensor.ipynb
• ParticleSwarmOptimizedPBS.ipynb
• misc/optimized_reflector.gds

Reverted (need library-side fixes, not notebook changes):

• HeatSolver.ipynb — TemperatureMonitor now defaults unstructured=True, returning TetrahedralGridDataset instead of SpatialDataArray. Notebook needs updating after the library API stabilizes.
• MetasurfaceBIC.ipynb — dictionary changed size during iteration in batch.run() is a tidy3d library bug.

Validation: rerun locally and committed the resulting notebook outputs / generated asset changes.

[daquinteroflex]

Notebook Fixes Summary

This PR fixes 4 notebooks that were failing in CI (run #23868661354) due to API changes, type validation, and deprecated NumPy functions. All notebooks were re-executed locally to regenerate outputs.

Fixes by notebook

1. MaxwellStressTensor.ipynb — NumPy 2.x API removal

• Error: AttributeError: module 'numpy' has no attribute 'trapz'
• Fix: Replaced all 9 calls of np.trapz(...) → np.trapezoid(...) (cell 7). np.trapz was removed in NumPy 2.0.

2. GeneticAlgorithmReflector.ipynb — Pydantic string_type validation

• Error: ValidationError: Input should be a valid string on tdd.ParameterInt(name=i, ...)
• Fix: Changed name=i → name=str(i) (cell 20). Pydantic v2 strict mode rejects integers where strings are expected.

3. ParticleSwarmOptimizedPBS.ipynb — Pydantic string_type validation

• Error: Same Pydantic validation as above on tdd.ParameterFloat(name=i, ...)
• Fix: Changed name=i → name=str(i) (cell 36).

4. DirectionalCouplerSurrogate.ipynb — Multi-element array to scalar conversion

• Error: TypeError: only 0-dimensional arrays can be converted to Python scalars
• Fix: Added np.squeeze() and .values before float() conversion after explode() (cell 20), since individual entries remain as 1-element DataArrays rather than 0-d scalars.

[github-actions]

Spell Check Report

DirectionalCouplerSurrogate.ipynb:

Cell 21, Line 14: '-element'
  > # We use .values to get the numpy array and .item() to safely convert a 1-element array to a float

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Checked 5 notebook(s). Found spelling errors in 1 file(s).
Generated by GitHub Action run: https://github.com/flexcompute/tidy3d-notebooks/actions/runs/24026563069

[momchil-flex]

Not urgent but I guess best to clear this

I am confused about the HeatSolver. It was fixed in this PR. I am not sure why your changes here seem to apply to an older version of the notebook.

[momchil-flex]

Oh regarding the HeatSolver it's supposed to be a revert? But I'm confused about the diff it shows here. Maybe some issue in notebook diff.