[meetdarc-tech]

Summary

Implements the pending-slash query, sequential migration coverage, Grafana dashboard import documentation, and evidence-hash validation requested by issues #1822-#1825.

Related Issue

• Enhancement: add get_pending_slashes view to oracle contract #1822 - Add a public view to list all pending slashes for an oracle.
• Test: migrate_state transitions storage correctly between sequential versions #1823 - Verify existing storage remains readable across sequential state migrations.
• Docs: docs/monitoring-setup.md Grafana dashboard import steps are missing #1824 - Document importing the pre-built Grafana dashboard.
• Security: dispute_oracle_result evidence hash is not validated to be a non-zero 32-byte value #1825 - Reject malformed and all-zero evidence hashes.

What Changed

• Contracts:
  • Added get_pending_slashes(oracle) backed by a per-oracle match index, kept consistent when a slash is staged, finalized, or cancelled.
  • Validate evidence hashes as non-zero 32-byte values encoded as 64 hexadecimal characters, returning InvalidEvidenceHash for invalid inputs.
• Tests:
  • Added pending-slash enumeration and lifecycle coverage.
  • Added sequential migration checks that verify the dispute period, match count, and stored match data remain readable.
  • Added zero-hash and malformed-hash rejection coverage and updated existing evidence fixtures to the validated format.
• Docs:
  • Added UI import steps and datasource selection details for the bundled Grafana dashboard.
  • Updated the InvalidEvidenceHash error reference.

Checklist

• cargo test passes locally - not run as requested.
• cargo clippy is clean - not run as requested.
• Tests added or updated for this change.
• Documentation updated (or no update needed).
• CHANGELOG.md updated under [Unreleased] - not changed.

closes #1822
closes #1823
closes #1824
closes #1825