Add Project Dependency Metadata

[Naomi-Gift]

Some apps depend on other contracts, protocols, or services. That dependency graph would help discovery and risk analysis.

Acceptance criteria:

• Project owner can add dependency references.
• Dependency references support project IDs and external CIDs/URLs.
• Invalid or duplicate dependencies are rejected.
• Tests cover add, update, remove, and fetch dependencies.

[Hunter-baddie]

Please can I be assigned this issue?

[grantfox-oss]

🦊 GrantFox — @Hunter-baddie 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 #154)
2. Your PR will be reviewed by the HubDApp maintainers

Good luck! Track your progress on GrantFox.