Fix cooldown fallback switching across model/runtime fallback hooks

src/hooks/runtime-fallback/error-classifier.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, test } from "bun:test"
+
+import { extractAutoRetrySignal, isRetryableError } from "./error-classifier"
+
+describe("runtime-fallback error classifier", () => {
+  test("detects cooling-down auto-retry status signals", () => {
+    //#given
+    const info = {
+      status:
+        "All credentials for model claude-opus-4-6-thinking are cooling down [retrying in ~5 days attempt #1]",
+    }
+
+    //#when
+    const signal = extractAutoRetrySignal(info)
+
+    //#then
+    expect(signal).toBeDefined()
+  })
+
+  test("treats cooling-down retry messages as retryable", () => {
+    //#given
+    const error = {
+      message:
+        "All credentials for model claude-opus-4-6-thinking are cooling down [retrying in ~5 days attempt #1]",
+    }
+
+    //#when
+    const retryable = isRetryableError(error, [400, 403, 408, 429, 500, 502, 503, 504, 529])
+
+    //#then
+    expect(retryable).toBe(true)
+  })
+
+  test("ignores non-retry assistant status text", () => {
+    //#given
+    const info = {
+      status: "Thinking...",
+    }
+
+    //#when
+    const signal = extractAutoRetrySignal(info)
+
+    //#then
+    expect(signal).toBeUndefined()
+  })
+})