fix: restore readMessagesFromSDK and its test

The previous commit incorrectly removed this function and its test
as dead code. While the local implementations in other files have
different return types (MessageData[], MessagePart[]) and cannot be
replaced by this shared version, the function is a valid tested
utility. Deleting tests is an anti-pattern in this project.

src/hooks/session-recovery/storage/readers-from-sdk.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "bun:test"
-import { readPartsFromSDK } from "../storage"
+import { readMessagesFromSDK, readPartsFromSDK } from "../storage"
 import { readMessages } from "./messages-reader"
 import { readParts } from "./parts-reader"
 
@@ -56,6 +56,28 @@ describe("session-recovery storage SDK readers", () => {
     expect(result).toEqual(storedParts)
   })
 
+  it("readMessagesFromSDK normalizes and sorts messages", async () => {
+    //#given a client that returns messages list
+    const sessionID = "ses_test"
+    const client = createMockClient({
+      messages: () => [
+        { id: "msg_b", role: "assistant", time: { created: 2 } },
+        { id: "msg_a", role: "user", time: { created: 1 } },
+        { id: "msg_c" },
+      ],
+    }) as Parameters<typeof readMessagesFromSDK>[0]
+
+    //#when readMessagesFromSDK is called
+    const result = await readMessagesFromSDK(client, sessionID)
+
+    //#then it returns sorted StoredMessageMeta with defaults
+    expect(result).toEqual([
+      { id: "msg_c", sessionID, role: "user", time: { created: 0 } },
+      { id: "msg_a", sessionID, role: "user", time: { created: 1 } },
+      { id: "msg_b", sessionID, role: "assistant", time: { created: 2 } },
+    ])
+  })
+
   it("readParts returns empty array for nonexistent message", () => {
     //#given a message ID that has no stored parts
     //#when readParts is called