s-ui-x-extended v1.0.0-hotfix3

Hotfix for the first stable release. No manual database migration is required.

Fixes

• Fixed Mieru and other extended protocol inbounds failing with users is empty when existing clients did not have per-protocol credentials. The backend now backfills missing protocol config blocks (passwords, UUIDs, mtproxy secrets) when clients are linked to an inbound, covering all three paths: new inbound, edit inbound, and bulk client edit.
• Hardened error handling in the credential backfill: UUID generation, shadowsocks password generation, and mtproxy secret generation now propagate errors instead of silently using empty values.

Verification

Checked locally with:

• go test ./... -count=1
• go vet ./...
• golangci-lint run ./service
• cd frontend && npm run test
• cd frontend && npm run lint
• cd frontend && npm run build