fix(windows): work around garbled control codes like we do on unix

cmd/dbc/drain_windows.go

@@ -16,6 +16,52 @@
 
 package main
 
-// no-op on Windows since I haven't reproduced this issue on a Windows terminal.
-// See drain_unix.go for a description of the issue and the fix.
-func suppressTerminalProbeResponses() {}
+import (
+	"os"
+	"time"
+
+	"golang.org/x/sys/windows"
+)
+
+// Work around https://github.com/columnar-tech/dbc/issues/351
+//
+// suppressTerminalProbeResponses prevents BubbleTea v2's capability probe
+// responses from appearing as garbled output in the shell. See drain_unix.go
+// for more detail on the problem.
+//
+// Unix restores raw mode and drains the tty with non-blocking reads. Windows
+// has no tty to drain: the fix is to discard the pending console input records
+// with FlushConsoleInputBuffer before we exit.
+//
+// Note this also discards genuine type-ahead the user entered while the command
+// was running. That matches the Unix drain, and is the accepted tradeoff: we
+// cannot distinguish a user's keystrokes from a terminal's DECRPM reply without
+// parsing the input records, and leaking escape sequences into the shell prompt
+// is the worse failure.
+func suppressTerminalProbeResponses() {
+	h := windows.Handle(os.Stdin.Fd())
+
+	// GetConsoleMode fails when stdin is not a console (piped or redirected
+	// input). In that case nothing was probed and nothing is buffered.
+	var mode uint32
+	if err := windows.GetConsoleMode(h, &mode); err != nil {
+		return
+	}
+
+	// Suppress echo while we wait, so a reply that arrives during the sleep is
+	// not written to the screen by the console host before we can flush it.
+	// This is belt-and-suspenders — the flush below is what actually fixes the
+	// reported symptom — so a failure here is not worth abandoning the flush.
+	if quiet := mode &^ (windows.ENABLE_ECHO_INPUT | windows.ENABLE_LINE_INPUT); quiet != mode {
+		if err := windows.SetConsoleMode(h, quiet); err == nil {
+			defer windows.SetConsoleMode(h, mode) //nolint:errcheck
+		}
+	}
+
+	// Give in-flight responses time to land in the input buffer before we
+	// discard it. The local round-trip is typically <5ms; 50ms gives headroom.
+	// Matches the Unix implementation in drain_unix.go.
+	time.Sleep(50 * time.Millisecond)
+
+	windows.FlushConsoleInputBuffer(h) //nolint:errcheck
+}