feat(validate-story): path rotation & persistence (ge-hch.3.4.2)

[SorraTheOrc]

Summary

Implements path rotation & persistence for scripts/validate-story.js (issue: ge-hch.3.4.2). Adds controlled retry behavior that rotates the model path on retry and optionally persists rotation state across runs.

What changed

• Adds path rotation: on retry, selects a new/next path instead of reusing the same failing path.
• Adds persistent state support to keep rotation progress across separate CLI invocations (opt-in via --state-file).
• Adds CLI flags:
  • --state-file <path>: where to read/write rotation state
  • --clear-state: delete/reset saved state before running
  • --max-retries <n>: maximum retry attempts (rotation happens on each retry)
• Maintains deterministic selection when seeded runs are used, while avoiding retrying the same path repeatedly.

Acceptance criteria

• Retries rotate to different paths instead of repeating the same path.
• When --state-file is provided, rotation state persists across runs.
• --clear-state resets the persisted rotation state.
• Default behavior remains unchanged unless new flags are used.

Test summary

• ✅ Most tests passing.
• ❌ One deterministic seeded run test currently failing (seeded determinism mismatch). Do not merge until resolved.

Instructions for reviewers

• Focus on:
  • Flag parsing/validation (--state-file, --clear-state, --max-retries).
  • Rotation behavior across retries (no repeated path on immediate retry).
  • State persistence semantics: file written/loaded at expected times; clear-state works.
  • Determinism: seeded path selection should remain stable given the same inputs, despite retries.

Merge checklist

• Fix the single failing deterministic seeded test.
• Confirm rotation + persistence behavior manually with --state-file.
• Ensure docs/usage and CHANGELOG entry are included in final PR.
• Re-run full test suite and post results in PR.