fix(api,admin-ui,user-ui): support described client scopes in admin and consent flows

[markwylde]

Summary

• store client scopes as structured key/description definitions and normalize legacy string inputs
• merge admin client create/edit into one page and let admins manage scope descriptions per scope key
• surface client-provided scope descriptions in the user consent UI, including backend support for lookup and authorize redirect propagation

Why

• scope keys alone are not enough context for end-user consent prompts and can lead to unclear permission screens
• admins needed a single workflow to both create and edit clients while managing scope metadata consistently
• token and seed handling needed normalization so structured scopes work safely across existing OAuth flows

Validation

• npm run tidy
• npm run build