Introduce progress bar updates and queue processing logic

Implemented progress bar integration with `ProgressBarContract` for real-time conversion tracking and status updates. Added queue management functionality to process files sequentially with error and completion handling. Extended `ConvertorContract` and `FFmpegContract` to support tracking of running processes and conversion progress.

internal/application/convertor/convertor.go

@@ -5,25 +5,54 @@ import (
 	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/application/convertor/encoder"
 	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/ffmpeg"
 	"io"
+	"os/exec"
 	"strings"
 )
 
 type ConvertorContract interface {
+	RunConvert(setting ffmpeg.ConvertSetting, progress ffmpeg.ProgressContract) error
 	GetSupportFormats() (encoder.ConvertorFormatsContract, error)
+	GetRunningProcesses() map[int]*exec.Cmd
+}
+
+type runningProcesses struct {
+	items          map[int]*exec.Cmd
+	numberOfStarts int
 }
 
 type convertor struct {
-	ffmpegService ffmpeg.UtilitiesContract
+	ffmpegService    ffmpeg.UtilitiesContract
+	runningProcesses *runningProcesses
 }
 
 func NewConvertor(
 	ffmpegService ffmpeg.UtilitiesContract,
 ) ConvertorContract {
 	return &convertor{
-		ffmpegService: ffmpegService,
+		ffmpegService:    ffmpegService,
+		runningProcesses: &runningProcesses{items: map[int]*exec.Cmd{}, numberOfStarts: 0},
 	}
 }
 
+func (c *convertor) RunConvert(setting ffmpeg.ConvertSetting, progress ffmpeg.ProgressContract) error {
+	ffmpegService, err := c.ffmpegService.GetFFmpeg()
+	if err != nil {
+		return err
+	}
+
+	index := c.runningProcesses.numberOfStarts
+	beforeWait := func(cmd *exec.Cmd) {
+		c.runningProcesses.numberOfStarts++
+		c.runningProcesses.items[index] = cmd
+	}
+
+	afterWait := func(cmd *exec.Cmd) {
+		delete(c.runningProcesses.items, index)
+	}
+
+	return ffmpegService.RunConvert(setting, progress, beforeWait, afterWait)
+}
+
 func (c *convertor) GetSupportFormats() (encoder.ConvertorFormatsContract, error) {
 	var err error
 
@@ -52,3 +81,7 @@ func (c *convertor) GetSupportFormats() (encoder.ConvertorFormatsContract, error
 
 	return formats, err
 }
+
+func (c *convertor) GetRunningProcesses() map[int]*exec.Cmd {
+	return c.runningProcesses.items
+}