Move serial port, trzsz filter, and pipe lifecycle into
internal/session.SerialSession. Replace 8 global I/O vars
(serialPort, trzszFilter, stdinPipe, stdoutPipe, clientIn,
clientOut, termch, termchOnce) with single sess variable.
Delete utils.go.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Extract ConvertChunk/FormatHexFrame into pkg/charset (zero external deps).
Extract UIEvent/UIEventKind/UIPanelKind types into internal/event.
Update all references across main package to use qualified imports.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Remove unused global var `in`, func `strout`, func `echoConsoleInput`,
func `padRight`, func `ErrorP`, and func `ErrorF`. Inline error check
in CloseSerial. Add COM.exe and coverage.out to .gitignore.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
JiXieShi