fix: enable runtime fallback for delegated child sessions (#2357)

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

@@ -1,6 +1,7 @@
-import { describe, expect, test } from "bun:test"
+declare const require: (name: string) => any
+const { describe, expect, test } = require("bun:test")
 
-import { extractAutoRetrySignal, isRetryableError } from "./error-classifier"
+import { classifyErrorType, extractAutoRetrySignal, isRetryableError } from "./error-classifier"
 
 describe("runtime-fallback error classifier", () => {
   test("detects cooling-down auto-retry status signals", () => {
@@ -45,6 +46,45 @@ describe("runtime-fallback error classifier", () => {
     expect(retryable).toBe(true)
   })
 
+  test("classifies ProviderModelNotFoundError as model_not_found", () => {
+    //#given
+    const error = {
+      name: "ProviderModelNotFoundError",
+      data: {
+        providerID: "anthropic",
+        modelID: "claude-opus-4-6",
+        message: "Model not found: anthropic/claude-opus-4-6.",
+      },
+    }
+
+    //#when
+    const errorType = classifyErrorType(error)
+    const retryable = isRetryableError(error, [429, 503, 529])
+
+    //#then
+    expect(errorType).toBe("model_not_found")
+    expect(retryable).toBe(true)
+  })
+
+  test("classifies nested AI_LoadAPIKeyError as missing_api_key", () => {
+    //#given
+    const error = {
+      data: {
+        name: "AI_LoadAPIKeyError",
+        message:
+          "Google Generative AI API key is missing. Pass it using the 'apiKey' parameter or the GOOGLE_GENERATIVE_AI_API_KEY environment variable.",
+      },
+    }
+
+    //#when
+    const errorType = classifyErrorType(error)
+    const retryable = isRetryableError(error, [429, 503, 529])
+
+    //#then
+    expect(errorType).toBe("missing_api_key")
+    expect(retryable).toBe(true)
+  })
+
   test("ignores non-retry assistant status text", () => {
     //#given
     const info = {