Adds WebRTC startup to the experimental app-server
`thread/realtime/start` method with an optional transport enum. The
websocket path remains the default; WebRTC offers create the realtime
session through the shared start flow and emit the answer SDP via
`thread/realtime/sdp`.
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Co-authored-by: Codex <noreply@openai.com>
Addresses #16560
Problem: `/status` stopped showing the source thread id in forked TUI
sessions after the app-server migration.
Solution: Carry fork source ids through app-server v2 thread data and
the TUI session adapter, and update TUI fixtures so `/status` matches
the old TUI behavior.
This addresses #16038
The default `tui_app_server` path stopped surfacing MCP startup failures
during cold start, even though the legacy TUI still showed warnings like
`MCP startup incomplete (...)`. The app-server bridge emitted per-server
startup status notifications, but `tui_app_server` ignored them, so
failed MCP handshakes could look like a clean startup.
This change teaches `tui_app_server` to consume MCP startup status
notifications, preserve the immediate per-server failure warning, and
synthesize the same aggregate startup warning the legacy TUI shows once
startup settles.
This is a follow-up to https://github.com/openai/codex/pull/15922. That
previous PR deleted the old `tui` directory and left the new
`tui_app_server` directory in place. This PR renames `tui_app_server` to
`tui` and fixes up all references.
PR https://github.com/openai/codex/pull/14512 added an in-process app
server and started to wire up the tui to use it. We were originally
planning to modify the `tui` code in place, converting it to use the app
server a bit at a time using a hybrid adapter. We've since decided to
create an entirely new parallel `tui_app_server` implementation and do
the conversion all at once but retain the existing `tui` while we work
the bugs out of the new implementation.
This PR undoes the changes to the `tui` made in the PR #14512 and
restores the old initialization to its previous state. This allows us to
modify the `tui_app_server` without the risk of regressing the old `tui`
code. For example, we can start to remove support for all legacy core
events, like the ones that PR https://github.com/openai/codex/pull/14892
needed to ignore.
Testing:
* I manually verified that the old `tui` starts and shuts down without a
problem.
This PR is part of the effort to move the TUI on top of the app server.
In a previous PR, we introduced an in-process app server and moved
`exec` on top of it.
For the TUI, we want to do the migration in stages. The app server
doesn't currently expose all of the functionality required by the TUI,
so we're going to need to support a hybrid approach as we make the
transition.
This PR changes the TUI initialization to instantiate an in-process app
server and access its `AuthManager` and `ThreadManager` rather than
constructing its own copies. It also adds a placeholder TUI event
handler that will eventually translate app server events into TUI
events. App server notifications are accepted but ignored for now. It
also adds proper shutdown of the app server when the TUI terminates.
