refactor: restructure codebase to internal/ directory with modular architecture

- Move all source files to internal/{app,backend,config,executor,logger,parser,utils}
- Integrate third-party libraries: zerolog, goccy/go-json, gopsutil, cobra/viper
- Add comprehensive unit tests for utils package (94.3% coverage)
- Add performance benchmarks for string operations
- Fix error display: cleanup warnings no longer pollute Recent Errors
- Add GitHub Actions CI workflow
- Add Makefile for build automation
- Add README documentation

Generated with SWE-Agent.ai

Co-Authored-By: SWE-Agent.ai <noreply@swe-agent.ai>

codeagent-wrapper/internal/logger/process_check.go

@@ -0,0 +1,63 @@
+package logger
+
+import (
+	"errors"
+	"math"
+	"time"
+
+	"github.com/shirou/gopsutil/v3/process"
+)
+
+func pidToInt32(pid int) (int32, bool) {
+	if pid <= 0 || pid > math.MaxInt32 {
+		return 0, false
+	}
+	return int32(pid), true
+}
+
+// isProcessRunning reports whether a process with the given pid appears to be running.
+// It is intentionally conservative on errors to avoid deleting logs for live processes.
+func isProcessRunning(pid int) bool {
+	pid32, ok := pidToInt32(pid)
+	if !ok {
+		return false
+	}
+
+	exists, err := process.PidExists(pid32)
+	if err == nil {
+		return exists
+	}
+
+	// If we can positively identify that the process doesn't exist, report false.
+	if errors.Is(err, process.ErrorProcessNotRunning) {
+		return false
+	}
+
+	// Permission/inspection failures: assume it's running to be safe.
+	return true
+}
+
+// getProcessStartTime returns the start time of a process.
+// Returns zero time if the start time cannot be determined.
+func getProcessStartTime(pid int) time.Time {
+	pid32, ok := pidToInt32(pid)
+	if !ok {
+		return time.Time{}
+	}
+
+	proc, err := process.NewProcess(pid32)
+	if err != nil {
+		return time.Time{}
+	}
+
+	ms, err := proc.CreateTime()
+	if err != nil || ms <= 0 {
+		return time.Time{}
+	}
+
+	return time.UnixMilli(ms)
+}
+
+func IsProcessRunning(pid int) bool { return isProcessRunning(pid) }
+
+func GetProcessStartTime(pid int) time.Time { return getProcessStartTime(pid) }