fix(coins): correct EIP-55 checksum of USDT0 on Rootstock

[maxklenk]

Problem

The USDT0 entry for Rootstock (ChainId.RSK, chain 30) carries an address whose mixed-case
casing is not a valid EIP-55 checksum:

0x779dED0C9e1022225F8e0630b35A9B54Be713736   <- in this repo, invalid checksum
0x779Ded0c9e1022225f8E0630b35a9b54bE713736   <- correct EIP-55

The same token on ChainId.STA (a few lines below, src/coins/coins.ts) already uses the
correct casing, so this is a one-off typo rather than an upstream address difference.

Consumers that pass the value straight through to a service comparing addresses verbatim get
a hard failure instead of a silent normalisation. Against the LI.FI API:

GET /v1/token?chain=30&token=0x779dED0C9e1022225F8e0630b35A9B54Be713736
  -> 404 Could not find token '0x779dED0C…' on chain '30'
GET /v1/token?chain=30&token=0x779Ded0c9e1022225f8E0630b35a9b54bE713736
  -> 200 USD₮0

findDefaultToken(CoinKey.USDT0, ChainId.RSK) is also what
STABLECOIN_COIN_KEYS-style resolution lands on for Rootstock, since the chain has no
canonical USDC/USDCe/BUSD/USDG/USDB/USDe entry — so every quote built against the default
Rootstock stablecoin 404s today.

Change

• Correct the checksum of the Rootstock USDT0 address. Address bytes are unchanged; only the
  casing differs.
• Add src/coins/coins.unit.spec.ts, an offline spec asserting every EVM token address in
  defaultCoins and wrappedTokens passes viem's isAddress(…, { strict: true }).
  All-lowercase addresses carry no checksum and stay valid, so the existing data is
  unaffected — only mis-cased addresses fail.

I audited the whole src/ tree: this was the only address of 722 with a broken checksum.

Verification

pnpm test          177 passed (2 files)
pnpm lint          clean
pnpm format:check  All matched files use the correct format.
pnpm typecheck     clean

The new spec fails before the data fix and passes after:

FAIL  src/coins/coins.unit.spec.ts > validate EVM token addresses > are valid EIP-55 addresses
+   "USDT0 on chain 30: 0x779dED0C9e1022225F8e0630b35A9B54Be713736",

Changeset: patch (data fix).

[changeset-bot]

🦋 Changeset detected

Latest commit: f503760

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@lifi/data-types	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR