Popiai can emit human-facing model names such as seedance2.0, while the upstream channel table is keyed by the canonical doubao-seedance model ids. Normalize Seedance aliases at the server gateway boundary so CLI, Popiai, and any direct gateway-compatible client can keep using friendly names without sending an unconfigured model id upstream.
Constraint: NewAPI channel selection requires canonical doubao-seedance-* model ids.
Rejected: Fix only the PopiArt CLI default path | Popiai and other clients can still send explicit friendly aliases.
Confidence: high
Scope-risk: narrow
Directive: Keep alias normalization at the server boundary before expanding client-specific mappings.
Tested: go test ./internal/server -run 'Seedance|VideoGenerations'
Tested: go test ./...