docs: document explicit input errors

[happykawayigt]

Description

Documents explicit input-validation exceptions in five public APIs as part of #1888.

Changes

• Add Google-style Raises sections to cyclic_permutation, amplitude_damping, bitflip, phase_damping, and ldot_channel.
• Cover invalid types, invalid probability/damping ranges, non-positive dimensions, and invalid LDOT matrix dimensions.

Validation

• ruff check on all five modified modules
• ruff format --check on all five modified modules
• Targeted tests for all five APIs (56 passed)
• Imported cyclic_permutation and verified the rendered docstring contains Raises:
• git diff --check
• GitHub Actions test and style checks passed

A full local MkDocs build was not run because mkdocs is unavailable in the local environment. The repository's Docs Preview check was skipped by its workflow configuration.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[vprusso]

Thanks @happykawayigt. I checked each Raises: entry against the actual validation code: amplitude_damping raises on both prob and gamma out of [0,1], bitflip on prob, phase_damping on gamma, ldot_channel on non-square and non-perfect-square dimension, and cyclic_permutation raises TypeError for non-integer n/k and ValueError for non-positive n. All five match. The added \([0,1]\) text is in raw docstrings, so no escape-sequence issue. Merging.