implement mapping rules engine & preflight modal in templates

[thopatevijay]

• Implement mapping.ts that maps IR -> control descriptors and validators.

• Implement components/ConfirmModal.tsx in templates showing accounts, signers, and estimated fee.

• Add simulate button in templates to call program.simulate before rpc() if Anchor supports.

Acceptance criteria

• Generated pages include preflight modal and simulate button.

• Filling forms and clicking Preview shows accurate accounts info pulled from IR.