feat: add `uact` denom support to frontend config

[baktun14]

Context

Part of AEP-76 BME migration. Add uact as a recognized denom in the deploy-web frontend configuration.

Tasks

• Add UACT_DENOM = "uact" and readable label in apps/deploy-web/src/config/denom.config.ts
• Add "uact" to NEXT_PUBLIC_MANAGED_WALLET_DENOM enum in apps/deploy-web/src/config/env-config.schema.ts

Acceptance Criteria

• Frontend recognizes uact as a valid managed wallet denom
• UACT_DENOM constant is available for use in hooks and components

Milestone

AEP-76: BME Migration — Phase 1 (Config & Types)

Reference

• AEP-76 Specification
• docs/aep-76-bme-migration-plan.md