feat(solana): add solana-safety-inspector and solana-pay-request plugins

[Transmetal]

Hi ZeroClaw team,

I have developed and submitted two secure, WASM-compliant Solana-native plugins to support Track A (Payments) and Track D (Onchain Safety) for the Superteam Brasil bounty:

1. solana-safety-inspector (T0 Read): Performs real-time on-chain safety verification of Token Mint addresses (mint and freeze authority renounced verification) via hand-rolled JSON-RPC requests.
2. solana-pay-request (T1 Build): Generates standard Solana Pay request URLs and instant, interactive scan-to-pay QR Codes for user wallet interface.

Both plugins feature clean, host-testable core logic (cargo test passes successfully) and compile cleanly to wasm32-wasip2. README files detailing the threat models, prompt-injection fail-closed defenses, and custody tiers are fully included.

Thank you!