refactor(cli): parse variants from model refs

packages/schema/test/model.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test"
+import { Model } from "../src/model.js"
+
+describe("Model.Ref", () => {
+  test("parses model references with optional variants", () => {
+    const variant = Model.Ref.parse("openrouter/openai/gpt-5#high")
+    expect(String(variant.providerID)).toBe("openrouter")
+    expect(String(variant.id)).toBe("openai/gpt-5")
+    expect(String(variant.variant)).toBe("high")
+
+    const standard = Model.Ref.parse("anthropic/claude-sonnet")
+    expect(String(standard.providerID)).toBe("anthropic")
+    expect(String(standard.id)).toBe("claude-sonnet")
+    expect(standard.variant).toBeUndefined()
+  })
+
+  test("rejects malformed model references", () => {
+    expect(() => Model.Ref.parse("gpt-5")).toThrow()
+    expect(() => Model.Ref.parse("openai/gpt-5#")).toThrow()
+    expect(() => Model.Ref.parse("openai/gpt-5#high#extra")).toThrow()
+  })
+})