feat: route Solana asset balance reads through Core AssetsController

[ulissesferreira]

Summary

• Bump snaps-sdk / platformVersion to 11.2.0 and add endowment:messenger for AssetsController:getAsset and AssetsController:getAssets.
• Replace Snap-owned balance persistence (AssetsRepository / assetEntities) with Core reads via a slim AssetsService (getAccountAssetByID, getAccountAssetsByIDs, getAccountAssets) and CoreAssetsAdapter.
• Rewire Keyring, Send, AccountsSynchronizer, and KeyringAccountMonitor so balances come from Core; WS monitoring keeps transaction discovery only. Metadata / market-data handlers stay Snap-side.

Test plan

• yarn workspace @metamask/solana-wallet-snap test
• Confirm Keyring listAccountAssets / getAccountBalances return Core-backed data under a client with AssetsController populated
• Confirm Send form loads balances and amount validation works
• Confirm account sync still saves transactions without writing Snap assetEntities
• Confirm WS account/program notifications still persist causing transactions and do not emit Snap balance updates
• Smoke onAssetsLookup / onAssetsMarketData

[mikesposito]

This repo is not accepting PRs anymore, as we are in the process of migrating it to https://github.com/MetaMask/internal-snaps

[ulissesferreira]

This repo is not accepting PRs anymore, as we are in the process of migrating it to https://github.com/MetaMask/internal-snaps

Yeah it will be moved when ready

[ulissesferreira]

Closing as superseded — this monolithic cutover was split into the stacked chain: #635 → #636 → #637, then either Lane A (#641 → #644 → #643) or Lane B (#638 → #639 → #640). Work lives on those branches.