## Why

Submitting a Solana transaction only proves RPC acceptance, leaving callers unable to distinguish a requested on-chain commitment outcome from an unknown pending or dropped transaction. A generic wait operation is needed so future consumers can explicitly await processed, confirmed, or finalized outcomes without coupling submission to confirmation.

## What Changes

- Add public Solana commitment and transaction-outcome types with strict status invariants and comprehensive timeout semantics.
- Add `SolanaBlockChain.awaitTransaction(...)` to poll `getSignatureStatuses` for an already submitted signature.
- Reuse the existing shared five-second RPC throttle while making gate acquisition interruptible and bounded by an overall monotonic deadline.
- Validate signatures and timeouts locally, strictly validate RPC responses, and reserve `FAILED` exclusively for on-chain execution errors observed at the requested commitment.
- Delegate every cached-wrapper call directly without caching or deduplication.
- Add the `SolanaSlot` ValueTag backed by nullable `Long`.

## Capabilities

### New Capabilities

- `solana-transaction-awaiting`: Generic blocking observation of an existing Solana transaction through a requested commitment level, with definitive success/failure and unknown-timeout semantics.

### Modified Capabilities

None.

## Impact

The Solana public API, reference RPC implementation, cached decorator, and shared Detag configuration are extended. Existing RPC operations retain their public behavior and common throttling; no wallet, Jupiter, burn, Evelyn, WebSocket, or transaction-submission consumer is changed to wait automatically.
