Validate service registration before allowing set_service_price

[mikewheeleer]

Harden set_service_price to require a registered service

Description

set_service_price in contracts/escrow/src/lib.rs accepts a price for any service_id, even one that was never registered, has no metadata, and is disabled. This lets prices accumulate for phantom services and makes the registry and pricing tables drift apart. This issue optionally couples pricing to registration so prices can only attach to real services.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-contracts only.
• Add an admin toggle (reusing the RequireServiceRegistration flag, or a parallel one) so that, when enabled, set_service_price rejects unregistered service_ids with ServiceNotRegistered.
• Optionally also reject pricing a disabled service, mirroring record_usage's ServiceDisabled gate.
• Keep the default behaviour backward-compatible (no coupling unless the flag is on) and document the interaction with strict-registration mode.
• Emit the price_set event only after the validation passes.

Suggested execution

• Fork the repo and create a branch
• git checkout -b enhancement/contracts-11-price-requires-registration
• Implement changes
  • Write code in: contracts/escrow/src/lib.rs — registration/disabled checks in set_service_price.
  • Write comprehensive tests in: contracts/escrow/src/test.rs — pricing unregistered service rejected when strict, allowed when lax.
  • Add documentation: clarify the coupling in README.md.
  • Include NatSpec-style doc comments (///) matching the existing style in lib.rs.
  • Validate security: no behaviour change when the flag is off.
• Test and commit

Test and commit

• Run cargo fmt --all -- --check, cargo build, and cargo test.
• Cover edge cases: registered+priced, unregistered+strict, disabled service, flag toggled mid-life.
• Include the full cargo test output and a short security notes section in the PR description.

Example commit message

feat: optionally require service registration before set_service_price

Guidelines

• Minimum 95 percent test coverage for impacted modules.
• Clear, reviewer-focused documentation.
• Timeframe: 96 hours.

Community & contribution rewards

• 💬 Join the AgentPay community on Discord for questions, reviews, and faster merges: https://discord.gg/eXvRKkgcv
• ⭐ This is a GrantFox OSS / Official Campaign task and may be rewarded. When your PR is merged you'll be prompted to rate the project — if this issue and the maintainers helped you ship, we'd be grateful for a 5-star rating. Clear questions in Discord and tidy, well-tested PRs are the fastest path to a merge and a reward.

[greatest0fallt1me]

Hello Maintainers 👋,
I’m interested in picking up this issue and contributing to the project.
I have solid experience working across both frontend and blockchain layers, including building user interfaces with Next.js and developing Stellar smart contracts using Rust (Soroban). I’m familiar with translating Figma designs into pixel-accurate UIs, handling wallet integrations, and writing efficient, well-tested contract logic.
I focus on writing clean, maintainable code, following repository standards, and keeping communication transparent throughout the development process. I can start immediately and complete the work within the expected timeframe.
Excited to collaborate and add value to the project 🚀
Thank you!

[grantfox-oss]

🦊 GrantFox — @greatest0fallt1me has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #11)
2. Your PR will be reviewed by the Agentpay-Org maintainers

Good luck! Track your progress on GrantFox.