Add missing Good/Bad/Ugly test triplets per RFC section 22:
- stats_test.go: OnAccept/OnReject/Tick/OnLogin/OnClose tests with
concurrency race test and top-10 diff slot verification
- ratelimit_test.go: full Good/Bad/Ugly set including ban persistence
and disabled-limiter edge case
- customdiff_test.go: renamed to Apply_Good/Bad/Ugly convention per RFC
- storage_test.go: full Add_Good/Bad/Ugly set including 256-slot fill,
overflow rejection, and dead-slot reclamation via SetJob
- job_test.go: added Good/Bad/Ugly for BlobWithFixedByte, DifficultyFromTarget,
and IsValid
Add Miner.Diff() public getter for the last difficulty sent to miner.
Add AX-compliant usage-example comments (principle 2) to all Miner
accessors, Proxy query methods, EffectiveShareDifficulty, targetFromDifficulty,
MinerSnapshot, and RateLimiter.IsActive.
Co-Authored-By: Virgil <virgil@lethean.io>
