Add send-input command with delayed enter and optional activation

[laffo16]

Summary

This adds a new wt send-input command for sending text to the active pane.

Included in this change:

• send-input <input...>
• --enter
• --enter-delay-ms <ms>
• --activate

Behavior notes:

• send-input targeting an existing window stays in the background by default
• send-input --activate opts back into the normal summon/foreground behavior
• focus-helper chains like focus-tab ; send-input stay background by default
• structural chains like new-tab ; send-input and split-pane ; send-input preserve existing activation behavior

Examples

wt -w 0 send-input "hello"
wt -w 0 send-input --enter "echo ready"
wt -w 0 send-input --enter --enter-delay-ms 200 "Please reply exactly with TEST_OK."
wt -w 0 send-input --activate "hello"
wt -w 0 focus-tab -t 1 ; send-input --enter "echo TAB2_OK"

Implementation Notes

• Reuses the existing SendInput action path
• Allows targeting existing windows without implicitly prepending new-tab for automation-style send/focus flows
• Preserves existing activation behavior for non-send structural command chains
• Keeps generated action IDs stable for zero-delay/default-args cases

Validation

Built successfully:

• SettingsModel.UnitTests.vcxproj
• TerminalApp.LocalTests.vcxproj

Focused tests passed:

• SettingsModelUnitTests::KeyBindingsTests::HashDeduplication
• SettingsModelUnitTests::KeyBindingsTests::DefaultArgSemanticDeduplication
• SettingsModelUnitTests::KeyBindingsTests::SendInputZeroDelayDeduplication
• SettingsModelUnitTests::KeyBindingsTests::SendInputDelayedEnterStaysDistinct
• TerminalAppLocalTests::CommandlineTest::ParseSendInputArgs

Manual smoke also passed against a side-by-side patched Terminal Dev package:

• background send-input
• --activate
• focus-tab ; send-input
• Codex prompt submission using --enter --enter-delay-ms

[laffo16]

@microsoft-github-policy-service agree

[DHowett]

I'm sorry, but we will not be accepting any work that adds a remote input injection vulnerability to Windows Terminal. Adding a wt send-input command will allow any application on the computer to inject input into any running instance of Terminal, unauthenticated, potentially controlling remote servers or admin sessions.