Add Solana TypeScript vault depositor

[ihsraham]

Summary

Adds Solana support to the TypeScript SDK vault depositor flow.

This PR includes native SOL and SPL token deposit support, transaction verification, Solana-specific validation, exports from the SDK entrypoint, integration coverage against the local validator, and a basic browser UI demo.

Changes

• Added SolanaVaultDepositor under sdk/ts/src/blockchain/sol.
• Added support for native SOL deposits and SPL token deposits.
• Added Solana transaction verification returning absent, pending, or confirmed status.
• Added Solana address, amount, reference, mint, commitment, and transaction reference validation.
• Reused the shared VaultDepositor destination shape with nested destination.account and optional destination.ref.
• Added unit tests and Docker-backed Solana integration tests.
• Added a basic Solana deposit browser demo using Wallet Standard signing and configured-RPC submission.
• Updated TS package scripts, CI, Makefile, and devnet docs for Solana test/demo coverage.

Demo

Validation

• npm --prefix sdk/ts run typecheck
• npm --prefix sdk/ts --workspace @yellow-org/solana-deposit-demo run build
• npm --prefix sdk/ts audit --omit=dev
• git diff --check
• Manual local browser demo: submitted and verified a SOL deposit against the local validator.

[nksazonov]

Clean, well-tested implementation — a few cleanup items and two small bugs worth addressing before merge.

[nksazonov]

All review items addressed. Approved.