fix(wta): reconnect via master pipe after FRE login (first-tab session view empty)

[DDKinger]

Symptom

After FRE, running copilot (or any agent CLI) in tab 1's shell pane produces a session that tab 1's session view never shows, even though the underlying ~/.copilot/session-state/<uuid>/ dir exists and the hook fires correctly. Tabs 2/3 (opened after login) work fine and even see tab 1's session because their helpers reach master via the standard pipe. Repro from a user log (0.1.1522.0): * wta-main_helper-16548.log (tab 1's helper): * line 19: ERROR helper: run_acp_client_over_pipe failed error=... Authentication required * line 21: AgentError auth fallback: showing setup screen * line 23-29: user does FRE login, acp: try_start_acp triggered has_event_tx=true has_deferred=true * line 33 onward (every 5s, forever): WARN agents_view: sessions/list ext-request failed error=Error { code: -32601: Method not found, message: "\"Method not found\": _intellterm.wta/sessions/list", ... } — note the underscore prefix * line 43: WARN session_hook: failed to queue session_hook event for master error=channel closed * wta-main_master.log: helper 1 connects once at 06:46:44 then never again. The session for tab 1 (sid 8514730f) only reaches master because tab 2's helper happens to forward the broadcast hook.

Root cause

In helper mode (--connect-master) the initial run_acp_client_over_pipe task fails immediately with Authentication required when the user is in FRE / not yet logged in. The post-login LoginComplete handler then fires try_start_acp, but that path was hard-wired to spawn run_acp_client (direct mode) instead of run_acp_client_over_pipe. The reconnected helper: * spawns its own copilot CLI subprocess and bypasses wta-master entirely (never re-registers with master), * every intellterm.wta/... ext-request fails with Method not found — the ACP SDK forwards unknown extensions to the agent with a leading _, and the directly-spawned agent CLI doesn't know master-side extensions, * the alive-mirror never populates → the first tab's session view stays blank for the helper's lifetime, * session_hook publishes log channel closed (the rx was consumed and dropped with the failed initial task).

Fix

Extend DeferredAcpParams with master_pipe_name and owner_tab_id (None in direct mode). * New App::set_master_pipe_acp_params, called once at boot in helper mode from main.rs to pre-stash pipe-mode params on App. * try_start_acp branches on master_pipe_name.is_some(): * pipe-mode reconnect: rebuilds the session_hook channel, re-binds self.session_hook_tx so hooks reach master again, spawns run_acp_client_over_pipe with the original pipe / owner_tab. * direct-mode: unchanged. * Existing set_acp_params and LoginComplete direct-mode synthesis paths just carry the two new fields as None. Why pre-stash instead of recreating from scratch in LoginComplete: keeps the pipe-mode discovery in main.rs alongside the rest of the helper-mode wiring (single place that knows about --connect-master), and LoginComplete's deferred_acp.is_none() synthesis path stays purely about the legacy direct-mode FRE.

Validation

Verified with a clean repro on 0.8.0.2:

Logout helper (deletes the only "logged-in state" source — Windows Credential
Manager target LegacyGeneric:target=copilot-cli/<host>:<user> — and
~/.copilot/config.json):

cmdkey /delete:LegacyGeneric:target=copilot-cli/https://github.com:<user>
Remove-Item "$env:USERPROFILE\.copilot\config.json" -Force

Repro / verify:

1. Run logout snippet → confirm cmdkey /list | findstr copilot is empty.
2. Launch Intelligent Terminal (FRE flag untouched) → agent pane in tab 1 shows GitHub login screen.
3. Complete login → tab 1 chat works, a session is created.
4. Open session view in tab 1 → new session appears.

Log signature (single line, easy to grep for future regressions):

	LoginComplete received: …
Before fix (wta-main_helper-23300.log)	deferred_acp=false → synthesizes direct-mode params → Spawning C:\…\copilot.exe… pid=Some(N) (own subprocess, bypasses master)
After fix (wta-main_helper-26644.log)	deferred_acp=true → try_start_acp: reconnecting via master pipe → run_acp_client_over_pipe → Session created (over pipe): <sid> → alive_mirror: alive session added by master

The deferred_acp=true|false boolean on the LoginComplete received line is the canonical externally-visible signature of the pre-stash — any future regression of this code path will flip it back to false.

cargo test --bin wta → 698 passed locally on x86_64-pc-windows-msvc.

Fixes #188.

[Copilot]

Pull request overview

Fixes a helper-mode (pipe-to-master) reconnection bug after FRE login where tab 1’s helper would fall back to direct-mode ACP, bypass wta-master, and therefore fail master-only intellterm.wta/... extension methods (leaving the session management view empty in the first tab).

Changes:

• Extend deferred ACP launch parameters to carry helper pipe-mode markers (master_pipe_name, owner_tab_id) so try_start_acp can reconnect through wta-master after login.
• Add a boot-time “pre-stash” in helper mode so post-FRE LoginComplete -> try_start_acp uses run_acp_client_over_pipe instead of run_acp_client.
• In try_start_acp, add a pipe-mode reconnect branch that rebuilds the session_hook channel and spawns the pipe transport.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
tools/wta/src/main.rs	Pre-stashes helper pipe-mode ACP params so post-FRE reconnect uses the master pipe transport.
tools/wta/src/app.rs	Adds pipe-mode fields to deferred params and branches try_start_acp to reconnect via master pipe, rebuilding hook plumbing.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.