Fix various issues around initial tty sizes + add test coverage

[OneBlue]

Summary of the Pull Request

This change fixes various codepaths were the initial tty size of a command wouldn't be correctly set.

To change this properly, the tty size is now passed when a container is started, not created. This is required to properly support the wslc create, followed by wslc start -a case, since the tty size might be different between the create and start call.

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[Copilot]

Pull request overview

This PR aims to ensure the initial TTY size is applied correctly for container init/exec processes by moving TTY sizing to “start time” (rather than “create time”), and adds both unit and E2E coverage (including ConPTY/pseudoconsole scenarios) to validate sizing behavior and error handling.

Changes:

• Introduces WSLCProcessStartOptions for passing TTY size (and detach keys) at container start/exec time, and threads TTY size through VM/root-namespace process creation.
• Updates wslc console attach/relay flows to consistently configure interactive console mode and to pass console state through helpers.
• Adds new TTY-size tests (invalid sizes rejected; expected size observed; pseudoconsole resize observed) across unit + E2E suites.

Reviewed changes

Copilot reviewed 28 out of 28 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test/windows/WSLCTests.cpp	Adds unit coverage for invalid TTY sizes and correct init/exec TTY sizing; updates Start calls to use new start options.
test/windows/wslc/e2e/WSLCExecutor.h	Adds PseudoConsole support and exposes stdout data + resize helpers for interactive sessions.
test/windows/wslc/e2e/WSLCExecutor.cpp	Implements ConPTY-backed interactive runs, stdout snapshotting, and pseudoconsole resizing support.
test/windows/wslc/e2e/WSLCE2EHelpers.h	Declares helper to validate pseudoconsole TTY sizing.
test/windows/wslc/e2e/WSLCE2EHelpers.cpp	Implements retry-based verification of initial + resized TTY size via pseudoconsole output.
test/windows/wslc/e2e/WSLCE2EContainerRunTests.cpp	Adds E2E test verifying container run -it respects initial/resized pseudoconsole size.
test/windows/wslc/e2e/WSLCE2EContainerExecTests.cpp	Adds E2E test verifying container exec -it respects initial/resized pseudoconsole size.
src/windows/wslcsession/WSLCVirtualMachine.h	Extends Linux process creation APIs to accept explicit TTY size.
src/windows/wslcsession/WSLCVirtualMachine.cpp	Threads TTY size through process creation and PTY fork paths.
src/windows/wslcsession/WSLCSession.h	Updates CreateRootNamespaceProcess signature to accept TTY size.
src/windows/wslcsession/WSLCSession.cpp	Passes TTY size through to VM process creation.
src/windows/wslcsession/WSLCContainer.h	Updates container Start/Exec APIs to take WSLCProcessStartOptions.
src/windows/wslcsession/WSLCContainer.cpp	Uses start options for detach keys and sets console size on exec; resizes container TTY after start.
src/windows/wslcsession/ServiceProcessLauncher.cpp	Passes stored rows/cols into VM process creation.
src/windows/wslc/services/SessionService.cpp	Ensures interactive console mode is configured and passes console state into attach flow.
src/windows/wslc/services/ContainerService.cpp	Computes and passes TTY size at start/exec time and threads console state through attach paths.
src/windows/wslc/services/ConsoleService.h	Updates console attach/relay signatures to accept a ConsoleState&.
src/windows/wslc/services/ConsoleService.cpp	Applies interactive mode configuration via passed-in ConsoleState.
src/windows/service/inc/wslc.idl	Introduces WSLCProcessStartOptions and changes COM method signatures to accept it / pass TTY sizing separately.
src/windows/service/exe/PluginManager.cpp	Updates call to new CreateRootNamespaceProcess signature.
src/windows/common/WSLCProcessLauncher.h	Changes default TTY size defaults (24x80) and stores size separately from process options.
src/windows/common/WSLCProcessLauncher.cpp	Moves TTY sizing into start options for exec/root namespace process creation.
src/windows/common/WslClient.cpp	Ensures interactive mode is configured for debug shell console usage.
src/windows/common/WSLCContainerLauncher.h	Exposes SetTtySize for container launcher.
src/windows/common/WSLCContainerLauncher.cpp	Passes TTY size via start options when starting a created container.
src/windows/common/svccomm.cpp	Ensures interactive mode is configured before reading console window size.
src/windows/common/ConsoleState.h	Adds SetInteractiveMode() and tracks whether interactive config was applied.
src/windows/common/ConsoleState.cpp	Splits interactive console configuration into an explicit method and improves state restoration semantics.