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/app/bench_test.go

@@ -0,0 +1,103 @@
+package wrapper
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	config "codeagent-wrapper/internal/config"
+)
+
+var (
+	benchCmdSink      any
+	benchConfigSink   *Config
+	benchMessageSink  string
+	benchThreadIDSink string
+)
+
+// BenchmarkStartup_NewRootCommand measures CLI startup overhead (command+flags construction).
+func BenchmarkStartup_NewRootCommand(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		benchCmdSink = newRootCommand()
+	}
+}
+
+// BenchmarkConfigParse_ParseArgs measures config parsing from argv/env (steady-state).
+func BenchmarkConfigParse_ParseArgs(b *testing.B) {
+	home := b.TempDir()
+	b.Setenv("HOME", home)
+	b.Setenv("USERPROFILE", home)
+
+	config.ResetModelsConfigCacheForTest()
+	b.Cleanup(config.ResetModelsConfigCacheForTest)
+
+	origArgs := os.Args
+	os.Args = []string{"codeagent-wrapper", "--agent", "develop", "task"}
+	b.Cleanup(func() { os.Args = origArgs })
+
+	if _, err := parseArgs(); err != nil {
+		b.Fatalf("warmup parseArgs() error: %v", err)
+	}
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		cfg, err := parseArgs()
+		if err != nil {
+			b.Fatalf("parseArgs() error: %v", err)
+		}
+		benchConfigSink = cfg
+	}
+}
+
+// BenchmarkJSONParse_ParseJSONStreamInternal measures line-delimited JSON stream parsing.
+func BenchmarkJSONParse_ParseJSONStreamInternal(b *testing.B) {
+	stream := []byte(
+		`{"type":"thread.started","thread_id":"t"}` + "\n" +
+			`{"type":"item.completed","item":{"type":"agent_message","text":"hello"}}` + "\n" +
+			`{"type":"thread.completed","thread_id":"t"}` + "\n",
+	)
+	b.SetBytes(int64(len(stream)))
+
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		message, threadID := parseJSONStreamInternal(bytes.NewReader(stream), nil, nil, nil, nil)
+		benchMessageSink = message
+		benchThreadIDSink = threadID
+	}
+}
+
+// BenchmarkLoggerWrite 测试日志写入性能
+func BenchmarkLoggerWrite(b *testing.B) {
+	logger, err := NewLogger()
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer logger.Close()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		logger.Info("benchmark log message")
+	}
+	b.StopTimer()
+	logger.Flush()
+}
+
+// BenchmarkLoggerConcurrentWrite 测试并发日志写入性能
+func BenchmarkLoggerConcurrentWrite(b *testing.B) {
+	logger, err := NewLogger()
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer logger.Close()
+
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			logger.Info("concurrent benchmark log message")
+		}
+	})
+	b.StopTimer()
+	logger.Flush()
+}