Mainnet deployment dry-run against futurenet

[truthixify]

Tier: M (2-4 days) Type: feature

Context

Our deploy.sh supports --dry-run but we have not actually run a full futurenet deployment end-to-end with the post-feature contracts (#42 splitter, #46 attestation build, etc). Need to verify the script works and capture the resulting addresses.

Scope

• Run the deploy script against futurenet with the current develop HEAD
• Capture and commit stellar/deployments/futurenet.json
• Verify each contract responds to a basic read call
• Document any gotchas hit during the run

Acceptance criteria

• stellar/deployments/futurenet.json committed
• Each contract reachable via Stellar Expert
• DEPLOYMENT.md updated with the dry-run procedure followed
• Cost report: total XLM spent across all contract uploads + inits

Files to start with

• stellar/deploy.sh
• stellar/build/build.sh
• stellar/MAINNET_READINESS.md