v0.3.1 — visible liveness, and two 0.3.0 defects

v0.3.1 — visible liveness, and two 0.3.0 defects

UPGRADE IF YOU ARE ON 0.3.0. Two of these are startup/connectivity defects.

• The Docker entrypoint still required ENGY_SN53_API and
  ENGY_SN53_MASTER_HOTKEY, so a container configured per 0.3.0's own
  documentation - wallet only - refused to start. Fixed; those two are
  optional everywhere now.

• The provider renamed /weights/latest to /epoch/latest with no alias.
  0.3.0 requests the old path and gets 404 on every poll. Staging already
  serves only the new path; production has not been redeployed yet.

• Every tick now logs. The two skipped:too-soon paths were silent, and with
  a 300s poll and a ~24min resubmit interval four ticks in five skip, so a
  healthy validator and a wedged one looked identical to anyone tailing the
  logs. Each skip now reports which epoch is already submitted and how long
  until the next resubmit.

Required configuration is still just your wallet:

ENGY_SN53_WALLET=<your wallet name>
ENGY_SN53_WALLET_HOTKEY=<your hotkey name>