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/utils/math_test.go

@@ -0,0 +1,36 @@
+package utils
+
+import "testing"
+
+func TestMin(t *testing.T) {
+	tests := []struct {
+		name string
+		a, b int
+		want int
+	}{
+		{"a less than b", 1, 2, 1},
+		{"b less than a", 5, 3, 3},
+		{"equal values", 7, 7, 7},
+		{"negative a", -5, 3, -5},
+		{"negative b", 5, -3, -3},
+		{"both negative", -5, -3, -5},
+		{"zero and positive", 0, 5, 0},
+		{"zero and negative", 0, -5, -5},
+		{"large values", 1000000, 999999, 999999},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := Min(tt.a, tt.b)
+			if got != tt.want {
+				t.Errorf("Min(%d, %d) = %d, want %d", tt.a, tt.b, got, tt.want)
+			}
+		})
+	}
+}
+
+func BenchmarkMin(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Min(i, i+1)
+	}
+}