fix(statics): route Polygon ERC-20 send-many via ERC-20 batcher

[bitgo-ai-agent-dev]

What

• Adds CoinFeature.ERC20_BULK_TRANSACTION to POLYGON_TOKEN_FEATURES, POLYGON_TOKEN_FEATURES_EXCLUDE_SINGAPORE, and POLYGON_TOKEN_FEATURES_WITH_FRANKFURT so every polygon:* / tpolygon:* ERC-20 token now advertises the ERC-20 bulk routing capability — mirroring what the polygon coin-level features already declare.
• Adds a coverage test in modules/statics/test/unit/coins.ts asserting every polygon: / tpolygon: token exposes ERC20_BULK_TRANSACTION, so this flag cannot regress for an individual token.

Why

Customers running sendMany for polygon:usdt on Polygon mainnet had their batched transfer encoded as sendMultiSigToken(batchContract, totalAmount, ...) on the PolygonWalletSimple proxy instead of batchTransferFrom(token, [recipients], [amounts]) on the BatchTransfer contract. The combined token amount was transferred to the batch contract as a single recipient (e.g. 2 USDT base units stuck at 0x3E1e5d78e44f15593B3B61ED278f12C27F0fF33e on mainnet, tx 0xbcbcf2e2...) rather than being split across the intended addresses.

Root cause: the ERC-20 batch routing checks token-level features, and polygon:usdt (along with every other Polygon ERC-20 token in the catalog) was only declaring BULK_TRANSACTION, not ERC20_BULK_TRANSACTION. The token therefore fell through to the native batcher path. Adding the flag aligns Polygon tokens with the existing convention used by the polygon coin-level features.

Test plan

• cd modules/statics && yarn unit-test — 30,585 passing, including the new Polygon ERC-20 tokens should have ERC20_BULK_TRANSACTION feature test
• cd modules/statics && yarn check-fmt
• Re-run a sendMany for polygon:usdt on Amoy / mainnet once the package is published, and confirm the on-chain method selector is 0x4885b254 (batchTransferFrom) and the call target is the BatchTransfer contract rather than the PolygonWalletSimple proxy.

Ticket: COINS-435

[linear-code]

COINS-435