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/utils_test.go

@@ -0,0 +1,143 @@
+package wrapper
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestExtractCoverage(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{"bare int", "92%", "92%"},
+		{"bare float", "92.5%", "92.5%"},
+		{"coverage prefix", "coverage: 92%", "92%"},
+		{"total prefix", "TOTAL 92%", "92%"},
+		{"all files", "All files 92%", "92%"},
+		{"empty", "", ""},
+		{"no number", "coverage: N/A", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := extractCoverage(tt.in); got != tt.want {
+				t.Fatalf("extractCoverage(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestExtractTestResults(t *testing.T) {
+	tests := []struct {
+		name       string
+		in         string
+		wantPassed int
+		wantFailed int
+	}{
+		{"pytest one line", "12 passed, 2 failed", 12, 2},
+		{"pytest split lines", "12 passed\n2 failed", 12, 2},
+		{"jest format", "Tests: 2 failed, 12 passed, 14 total", 12, 2},
+		{"go test style count", "ok\texample.com/foo\t0.12s\t12 tests", 12, 0},
+		{"zero counts", "0 passed, 0 failed", 0, 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			passed, failed := extractTestResults(tt.in)
+			if passed != tt.wantPassed || failed != tt.wantFailed {
+				t.Fatalf("extractTestResults(%q) = (%d, %d), want (%d, %d)", tt.in, passed, failed, tt.wantPassed, tt.wantFailed)
+			}
+		})
+	}
+}
+
+func TestExtractFilesChanged(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want []string
+	}{
+		{"root file", "Modified: main.go\n", []string{"main.go"}},
+		{"path file", "Created: codeagent-wrapper/utils.go\n", []string{"codeagent-wrapper/utils.go"}},
+		{"at prefix", "Updated: @codeagent-wrapper/main.go\n", []string{"codeagent-wrapper/main.go"}},
+		{"token scan", "Files: @main.go, @codeagent-wrapper/utils.go\n", []string{"main.go", "codeagent-wrapper/utils.go"}},
+		{"space path", "Modified: dir/with space/file.go\n", []string{"dir/with space/file.go"}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := extractFilesChanged(tt.in); !reflect.DeepEqual(got, tt.want) {
+				t.Fatalf("extractFilesChanged(%q) = %#v, want %#v", tt.in, got, tt.want)
+			}
+		})
+	}
+
+	t.Run("limits to first 10", func(t *testing.T) {
+		var b strings.Builder
+		for i := 0; i < 12; i++ {
+			fmt.Fprintf(&b, "Modified: file%d.go\n", i)
+		}
+		got := extractFilesChanged(b.String())
+		if len(got) != 10 {
+			t.Fatalf("len(files)=%d, want 10: %#v", len(got), got)
+		}
+		for i := 0; i < 10; i++ {
+			want := fmt.Sprintf("file%d.go", i)
+			if got[i] != want {
+				t.Fatalf("files[%d]=%q, want %q", i, got[i], want)
+			}
+		}
+	})
+}
+
+func TestSafeTruncate(t *testing.T) {
+	tests := []struct {
+		name   string
+		in     string
+		maxLen int
+		want   string
+	}{
+		{"empty", "", 4, ""},
+		{"zero maxLen", "hello", 0, ""},
+		{"one rune", "你好", 1, "你"},
+		{"two runes no truncate", "你好", 2, "你好"},
+		{"three runes no truncate", "你好", 3, "你好"},
+		{"two runes truncates long", "你好世界", 2, "你"},
+		{"three runes truncates long", "你好世界", 3, "你"},
+		{"four with ellipsis", "你好世界啊", 4, "你..."},
+		{"emoji", "🙂🙂🙂🙂🙂", 4, "🙂..."},
+		{"no truncate", "你好世界", 4, "你好世界"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := safeTruncate(tt.in, tt.maxLen); got != tt.want {
+				t.Fatalf("safeTruncate(%q, %d) = %q, want %q", tt.in, tt.maxLen, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSanitizeOutput(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{"ansi", "\x1b[31mred\x1b[0m", "red"},
+		{"control chars", "a\x07b\r\nc\t", "ab\nc\t"},
+		{"normal", "hello\nworld\t!", "hello\nworld\t!"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := sanitizeOutput(tt.in); got != tt.want {
+				t.Fatalf("sanitizeOutput(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
+	}
+}