Add network-specific SDK entrypoints

[zjma]

Summary

• add @aptos-labs/ace-sdk/aptos and @aptos-labs/ace-sdk/solana subpath exports
• mark @solana/web3.js as an optional peer dependency
• remove SDK runtime imports of @solana/web3.js by serializing Solana proof data from bytes
• bump NEXT_RELEASE to 3.7.0 for the minor release

Testing

• pnpm --filter @aptos-labs/ace-sdk build
• pnpm --filter @aptos-labs/ace-sdk typecheck
• pnpm --filter @aptos-labs/ace-sdk exec vitest run tests/solana-wire.test.ts
• pnpm --filter ace-scenarios typecheck
• local CJS import guard for root, /aptos, and /solana with @solana/web3.js blocked