fix(recipe): reject non-finite values for declared float recipe settings

[HeaTTap]

Motivation

Closes #225

Rejects NaN, positive infinity, and negative infinity for declared float recipe settings so invalid values fail fast during configuration resolution rather than silently altering sampling or blocking waits downstream.

Changes

• In reef/recipe/config_fields.py, update _parse_float to check math.isfinite on parsed floats and raise RecipeConfigError if the value is non-finite.
• In tests/reef_service/test_recipe_config_fields.py, add unit tests asserting NaN, positive infinity, and negative infinity are rejected from numeric config, string config, YAML, and environment fallback, while preserving parsing for valid finite numbers.

Compatibility and operational impact

None. Declared float recipe settings require finite numbers.

Verification

Ran:

• pytest tests/reef_service/test_recipe_config_fields.py (41 passed)
• python3 .github/scripts/check_python_design.py (passed)
• python3 .github/scripts/check_python_statements.py (passed)
• pre-commit checks on all files (passed)

AI assistance

None

Checklist

• The change is focused and contains no unrelated cleanup.
• Tests cover behavior changes, or this pull request does not change behavior.
• Public interface changes include contract tests, or no public interface changes are present.
• Affected user and developer documentation is updated, or no documentation update is required.
• An accepted RFC is linked, or this change does not require an RFC.
• Relevant pre-commit and test checks pass.
• Non-trivial AI assistance is disclosed above, or none was used.

[github-actions]

Merge Oncall: @BobbyZhouZijian

The merge oncall will route reviews and keep this pull request moving toward a clear decision.

[BobbyZhouZijian]

Hi @HeaTTap , thanks for the PR. Could you resolve the CI failures?