Track history notes thread hint outcomes (#42247)

## What changed

- Emit a `codex_thread_hint_status` analytics event for each native history-notes thread hint attempt.
- Report whether retrieval was successful or failed along with thread context and timing, without including hint contents.
- Treat valid empty responses as successful retrievals while continuing to omit them from the context window.

## Testing

- Extend the app-server history-notes tests to verify success, empty-result success, and backend failure statuses.

GitOrigin-RevId: b9462f312847e8c871ed2be0c8cf8df0928a7fdd

codex-rs/ext/history-notes/Cargo.toml

@@ -13,6 +13,7 @@ doctest = false
 workspace = true
 
 [dependencies]
+codex-analytics = { workspace = true }
 codex-api = { workspace = true }
 codex-client = { workspace = true }
 codex-core = { workspace = true }