chore: bump version to v2.0.13

[flyq]

Summary

Bumps the workspace version 2.0.12 → 2.0.13 and switches the mega-evm /
salt git dependencies from rev = "..." to tag = "...".

Changes

• Version bump — [workspace.package] version 2.0.12 → 2.0.13,
  propagated to all six member crates (stateless-validator,
  debug-trace-server, stateless-core, stateless-db, stateless-common,
  stateless-test-utils) via version.workspace = true.
• Git dependency pinning — mega-evm (v1.6.0) and salt (v1.0.4) now
  reference their git tag instead of rev. The resolved commits are
  unchanged (mega-evm → be4418d, salt → 9978132), so this is purely a
  source-specifier cleanup with no dependency drift.
• Cargo.lock regenerated to reflect both changes.

[claude]

LGTM. Clean version bump with the rev → tag cleanup being a nice semantic improvement (same commit pinned in the lock file, just makes intent explicit).

[claude]

The PR currently has no labels applied.

Based on the diff, this is a purely mechanical change: the git dependency specifiers for mega-evm and salt are switched from rev to tag (resolving to the exact same commits), and the workspace version is bumped from 2.0.12 to 2.0.13. There are no behavior changes, no API changes, and no dependency drift.

The compat:seamless label appears to be missing — this change is a textbook seamless/backward-compatible update with no risk of breakage.