noter: prove a stake from the hub's own state once the People chain takes proofs (#39)

The People chain is gaining `prove_stake` (pezkuwi-DKS #132): a stake is proven from the Asset
Hub's own state through a relay-anchored storage proof, instead of a noter reporting it and
re-confirming it every three days -- which does not fit at forty million.

When the People chain's metadata has `stakingScore.proveStake`, the bot:
- builds the proof (`prove.js`): the relay parent of People's best block, which People kept in
  `RelayRoots`; the relay proof of `Paras::Heads(1000)` there; the hub proof of the account's
  `Staking::Bonded`/`Ledger`/`Nominators`, `NominationPools::PoolMembers`, and for a member the
  pool and its bonded account;
- submits it when the hub's figure differs from the People chain's, or when what People holds
  was never proven; never re-confirms an unchanged, proven stake;
- watches the Asset Hub's finalized blocks for staking and pool events and proves the tracked
  accounts they touch as they happen; the periodic scan stays as a safety net.

Before the upgrade nothing changes: the noter path is used as today. The bot's own reading only
decides when to prove; what lands is what the proof says. `prove.test.mjs` pins the pool account
derivation against Zagros pool 10.

.github/workflows/ci.yml

@@ -85,7 +85,7 @@ jobs:
       # Run inside the image, so the modules under test are the ones the image ships.
       - name: Unit tests
         if: matrix.bot == 'noter'
-        run: docker run --rm -v "$PWD/noter/test:/app/test:ro" bot node --test test/submit.test.mjs test/confirm.test.mjs
+        run: docker run --rm -v "$PWD/noter/test:/app/test:ro" bot node --test test/submit.test.mjs test/confirm.test.mjs test/prove.test.mjs
 
       - name: The bot loads and stops at its missing mnemonic
         env: