Don't prompt to restart Extension Terminal on shutdown (#4101, #4145)

[andyleejordan]

Summary

Fixes #4101 and #4145, two related bugs with the "The PowerShell Extension Terminal has stopped, would you like to restart it?" prompt.

• During closing VSCode, PowerShell Extension displays popup #4101 — prompt during VS Code shutdown: When VS Code closes or reloads the window it disposes our Extension Terminal, firing onDidCloseTerminal → PowerShellProcess.dispose() → onExited → promptForRestart(). Since that can happen before the extension's deactivate() runs, a status/disposal check alone misses it. We now capture the terminal's TerminalExitReason (finalized in VS Code 1.71) and bail out of the prompt when the reason is Shutdown, plus set an isDisposing flag in dispose() as a belt-and-suspenders guard.
• Double prompt when closing powershell extension terminal #4145 — double prompt: Nothing prevented the prompt from being shown more than once concurrently. Added an isPromptingForRestart guard (try/finally) so at most one is open at a time.

We still prompt on a genuine user-close (User) or process crash (Process), and the existing powershell.integratedConsole.suppressTerminalStoppedNotification behavior is preserved.

Changes

• src/process.ts: capture terminal.exitStatus?.reason on close, exposed as terminalExitReason.
• src/session.ts: pass the exit reason into promptForRestart(); early-return on isDisposing or Shutdown (During closing VSCode, PowerShell Extension displays popup #4101) and dedupe with isPromptingForRestart (Double prompt when closing powershell extension terminal #4145).
• test/core/session.test.ts: 5 new tests (user-close prompts; suppressed while disposing; suppressed on shutdown; deduped concurrent prompts; respects the suppress setting).

Verification

• npm run compile, npm run lint, npm run format — clean.
• Full vscode-test suite: 109 passing, 4 pending, including the 5 new tests.

[Copilot]

Pull request overview

This PR fixes two related bugs with the "The PowerShell Extension Terminal has stopped, would you like to restart it?" prompt. It suppresses the prompt during VS Code shutdown/reload (issue #4101) by checking the terminal's TerminalExitReason and an isDisposing flag, and prevents duplicate concurrent prompts (issue #4145) with an isPromptingForRestart guard.

Changes:

• Captures TerminalExitReason in PowerShellProcess when the Extension Terminal closes and passes it through to promptForRestart, which early-returns on Shutdown or isDisposing.
• Guards promptForRestart with isPromptingForRestart (try/finally) so at most one prompt is shown at a time.
• Adds 5 targeted tests covering user-close prompts, shutdown suppression, dispose suppression, concurrent deduplication, and the suppress-notification setting.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/process.ts	Adds public terminalExitReason property, captured in onTerminalClose before dispose() fires onExited.
src/session.ts	Adds isDisposing and isPromptingForRestart guards; promptForRestart now accepts an optional TerminalExitReason and early-returns when the window is shutting down, the manager is disposing, or a prompt is already open.
test/core/session.test.ts	Adds a new describe("SessionManager restart prompt") block with 5 tests, a createSessionManager helper, and a promptForRestart test wrapper.

[andyleejordan]

Closing as redundant. On investigation, both #4101 and #4145 were already addressed by #5380 and #5463 (the April termination-experience rework): the double prompt is suppressed by the handled: true close action, and the shutdown popup no longer fires because the prompt is gated on Running/Busy while disposal sets Stopping first. The isDisposing/dedupe/TerminalExitReason guards here are defense-in-depth on top of fixes already on main, so I'm closing rather than adding churn.

_{🤖 Drafted by Copilot for @andyleejordan to review/edit.}

[andyleejordan]

(But I did like the approach with the terminal closed reasons...didn't know that was a thing.)