CC Uni Gate v0.1.4

Changes

• Add discovery-backed routable model candidates while keeping configured/custom models as the visible route source.
• Let custom models choose discovered provider/model targets.
• Keep model discovery refresh animation tied to the actual refresh lifecycle.
• Move toast notifications to the center and show model discovery completion only after refresh finishes.

Verification

• swift test
• Built macOS release bundle.
• Locally unzipped and launched the release app before publishing.