Add nova-2 to region prefix models (#8085)

Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>

packages/opencode/src/provider/provider.ts

@@ -237,6 +237,7 @@ export namespace Provider {
                 "nova-lite",
                 "nova-pro",
                 "nova-premier",
+                "nova-2",
                 "claude",
                 "deepseek",
               ].some((m) => modelID.includes(m))