Support remote app-server threads in Desktop thread orchestration

Summary

Remote-native Codex threads can be created on an SSH host, but Codex Desktop's local thread orchestration surface cannot list/read/manage those remote threads.

Repro

1. Start from a local Codex Desktop host with an SSH remote configured.
2. On the remote host, create a native app-server thread in a remote workspace:

ssh <host> 'cd <remote-workspace> && codex debug app-server send-message-v2 "Reply exactly REMOTE_NATIVE_OK"'

1. The remote host creates a real Codex thread with:

• remote cwd
• remote rollout under <remote CODEX_HOME>/sessions/...
• remote workspace instructions loaded

1. From the local Desktop thread orchestration surface, try to inspect that thread:

read_thread(<remote-thread-id>) -> thread not loaded
list_threads(query: <remote-thread-id>) -> no results

Expected

Codex Desktop should be able to treat remote app-server threads as first-class thread targets:

• list/search remote threads by host/workspace
• read remote thread status and recent turns
• create a remote thread with a specific remote cwd
• send follow-up prompts to a remote thread
• rename/title remote threads
• pin/unpin and archive/unarchive remote threads

Actual

The remote thread exists and is durable on the SSH host, but local Desktop thread orchestration cannot see or manage it. The current workaround is to create a local child thread that runs ssh <host> ..., which works but loses native thread identity, sidebar organization, and remote workspace ownership.

Why this matters

A local Director/orchestrator thread should be able to coordinate work across SSH remote workspaces without falling back to shell-level SSH wrappers.

Related

Related but broader/different:

• #23907
• #25092
• #23062
• #25454