Harden KOTH weight inputs and fallback

[kenobijon]

Summary

• overlay partial API split updates on the 40/40/4/16 defaults and reject non-numeric, non-finite, negative, or non-unit effective splits
• validate current and historical king addresses before caching or allocating weights
• expire last-known-good king data after 24 hours and require the owner/burn UID for every submission
• reject incomplete final weight vectors before Bittensor normalization
• fix the PM2 benchmark API argument name

Verification

• 73 tests passed
• CI-equivalent Ruff checks passed
• Python compile checks passed
• validator.config.js syntax check passed
• focused Bandit scan found no medium/high issues

---

Note

High Risk
Changes on-chain weight allocation and trust boundaries for external KOTH API data; mis-validation or cache behavior could mis-route emissions or burn discriminator share incorrectly.

Overview
Hardens King-of-the-Hill (KOTH) weight setting so validators only trust validated API data and fail safely when inputs are bad or stale.

Adds resolve_koth_split and validate_koth_payload: partial API splits overlay on protocol defaults; splits must be numeric, finite, non-negative, and sum to 1. Current-kings responses are normalized to kings, chain, and split only, with SS58 checks, one king per modality, and chain heads aligned with current kings.

build_koth_weights now requires a valid owner/burn UID before building weights, deduplicates generator UIDs, and rejects non-unit or invalid final vectors. Modality lists use KOTH_MODALITIES.

The validator validates live and cached current-kings payloads, persists fetched_at with a 24-hour TTL (legacy caches without timestamps are treated stale), and falls back to empty kings plus KOTH_SPLIT when nothing valid is available—discriminator share burns with clearer logging.

validator.config.js fixes the PM2 CLI flag to --benchmark-api-url. New tests cover cache TTL/persistence and validation edge cases.

^{Reviewed by Cursor Bugbot for commit 234932a. Bugbot is set up for automated code reviews on this repo. Configure here.}