Fix panic when recording apps that output non-UTF-8 bytes

[SteveSandersonMS]

Windows console in UTF-8 mode rejects non-UTF-8 byte sequences via std::io::stdout().write(), causing a panic.

This PR:

• Uses WriteConsoleW to write directly to the console handle, bypassing Rust's UTF-8 validation
• Buffers incomplete UTF-8 sequences across chunk boundaries to prevent replacement characters when multi-byte chars are split between reads

Fixes #243

[Copilot]

Pull request overview

This PR fixes a panic that occurs when recording applications that output non-UTF-8 byte sequences on Windows. The issue stems from Windows console in UTF-8 mode rejecting invalid UTF-8 sequences through Rust's standard output validation.

Changes:

• Replaces std::io::stdout().write() with direct WriteConsoleW calls to bypass Rust's UTF-8 validation
• Implements buffering logic to handle incomplete UTF-8 sequences that may be split across chunk boundaries
• Ensures proper Unicode handling by converting valid UTF-8 strings to UTF-16 before writing to console

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[Copilot]

The stdout handle is retrieved once outside the loop, but if the handle becomes invalid during execution (e.g., console detachment), subsequent writes will fail. Consider retrieving the handle inside the loop or adding error handling to detect and recover from invalid handle states.

Suggested change

	#[cfg(windows)]
	let stdout_handle: HANDLE =
	unsafe { GetStdHandle(STD_OUTPUT_HANDLE).expect("failed to get stdout handle") };
	// Buffer for incomplete UTF-8 sequences split across chunk boundaries
	let mut pending_bytes: Vec<u8> = Vec::new();
	loop {
	// Buffer for incomplete UTF-8 sequences split across chunk boundaries
	let mut pending_bytes: Vec<u8> = Vec::new();
	loop {
	#[cfg(windows)]
	let stdout_handle: HANDLE =
	unsafe { GetStdHandle(STD_OUTPUT_HANDLE).expect("failed to get stdout handle") };

[ibigbug]

@SteveSandersonMS do you think this comment makes sense? (i'm not a Windows console expert :))

[ibigbug]

wow thank you so much! bar the Copilot comment