Add paginated history reads to the cloud client (#59075)

## Why

`Attach` delivers live events only. Clients also need access to stored turn metadata and item content.

## What changed

- Add `Client::list_turns` and `Client::list_items` using native gRPC history endpoints, with optional turn filtering for items.
- Expose page limits, sort order, access mode, and forward/backward cursors. Each call returns one page in server order without automatic pagination or retries.
- Preserve raw response and row payloads alongside typed summaries and item timestamps. Retain unknown item variants and command sources without typed summaries.
- Document cursor reuse and history/live overlap: history pages do not provide an atomic boundary with `Attach`, and coordinated reconciliation still requires caller-managed state.

## Testing

Add wire-fixture tests for request encoding, explicit pagination, raw payload preservation, unknown data, malformed rows, empty pages, RPC errors without retries, and diagnostic redaction.

GitOrigin-RevId: f507530b8e431236bc7e19d867517af56f74644f

codex-rs/cloud-client/src/transcript_tests.rs

@@ -295,3 +295,6 @@ fn notification_selection_handles_many_fragments_and_obsolete_malformed_messages
 
 #[path = "item_tests.rs"]
 mod items;
+
+#[path = "history_tests.rs"]
+mod history;