MIP-0004: Registration-Time Usernames for Address-Native Accounts

[christopherwxyz]

This discussion is for review and feedback on MIP-0004: Registration-Time Usernames for Address-Native Accounts.

Full text: mips/MIP-0004-registration-time-usernames.md
PR: #16
Original discussion: https://github.com/officialunofficial/makechain/discussions/388

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Summary

MIP-0004 adds a globally unique, storage-backed username namespace to address-native accounts:

• Usernames are assigned at first paid storage activation via STORAGE_CLAIM
• STORAGE_CLAIM becomes a delegated-key-authenticated message with SIGNING scope
• Usernames are immutable while an account has effective active storage
• Usernames are released when storage fully expires via lazy sweep
• Username index stored at state prefix 0x08
• Canonical format: ^[a-z0-9][a-z0-9-]{1,30}[a-z0-9]$ (3-32 chars, lowercase ASCII)
• GetAccountResponse extended with username field at number 18

Requires: MIP-0003 (address-native identity)

Author: @marthendalnunes

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Please review and share feedback on the proposal.