Run PTY and fake-tool integration tests on Windows

[skyrpex]

Motivation

Windows CI skipped ~48 integration tests in two whole categories: every PTY-based test (creack/pty has no Windows support) and every test faking an external CLI (aws, az, terraform, cdk, sam, aws_completer) with a #!/bin/sh script. That left the interactive paths — login flow, setup prompts, emulator selector, spinner behavior, --json TTY gating — with zero Windows coverage, exactly where OS-specific bugs (keyring, %AppData% paths, ConPTY rendering) would hide.

Solution

• Cross-platform PTY helpers (test/integration/pty_helpers_test.go): runLstkInPTY / startLstkInPTY / startCmdInPTY return a ptyProc with waitForOutput/write/wait/kill, backed by charmbracelet/x/xpty (Unix PTY on macOS/Linux, ConPTY on Windows). Output is ANSI-stripped (ConPTY injects its own repaint sequences), wait yields an *exec.ExitError on every platform, and the ConPTY buffer is wide (300 cols) so its line re-wrapping can't break substring assertions. All 31 direct pty.Start sites migrated; creack/pty remains only in the !windows-tagged signal-forwarding tests.
• Compiled fake tools (test-samples/faketool + faketool_test.go): one Go stand-in binary, built once per run and copied onto PATH under the impersonated name, driven by a JSON sidecar (placeholder echo lines, --version-style arg cases, sleep, exit codes, record-to-file). Replaces every shell-script fake, including aws_completer and the fake browser openers (rundll32 on Windows).
• Windows-correct env isolation: new env.WithHome(dir) sets HOME + USERPROFILE + APPDATA (Windows binaries read the latter two), swept across all 119 With(env.Home, ...) sites; unreachableDockerHost is now tcp://localhost:1 (valid on every OS, unlike a unix socket path).
• Skips: down from ~48 to 14, each with an accurate reason. What remains is inherent: Docker (requireDocker — no nested virtualization on Windows CI), unix-socket tests, POSIX signal/os.Interrupt tests, bash completion, symlink-permission tests, the two inner-PTY streaming tests (proc.RunInPTY is unix-only), and one read-only-directory permission test. One stale skip (az_interception, which uses no PTY) removed outright.

After this, Windows runs the same test set macOS does, modulo the inherent list above. Verified: go vet/build clean for darwin and GOOS=windows, make lint clean on both modules, unit tests pass, and the migrated integration tests (including interactive PTY flows) pass locally on macOS with Docker.

Docs

Nothing user-facing to document — test infrastructure only. CLAUDE.md's Testing section is updated in this PR with the new conventions (use the PTY helpers, use faketool instead of shell scripts, no convenience GOOS == "windows" skips, tcp://localhost:1 for unreachable Docker).

Review

Human review advisable: wide test-infrastructure change, and the ConPTY drain/close ordering in ptyProc.wait is behavior-sensitive. Real ConPTY behavior is only provable on Windows CI — watch that job for flakes in TUI-layout assertions (TestStatusEndpointURLInteractiveRendersTUI is the most at-risk).

🤖 Generated with Claude Code

[anisaoshafi]

Great job un-skipping so many tests, Cristian!
We gain more confidence around windows behaviour and avoid breaking things in the future 🪨
Thanks for challenging the status quo and finding this solution.

Skimmed through the code and looks good to me!