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/executor/report_helpers.go

@@ -0,0 +1,104 @@
+package executor
+
+import "strings"
+
+// extractCoverageGap extracts what's missing from coverage reports.
+func extractCoverageGap(message string) string {
+	if message == "" {
+		return ""
+	}
+
+	lower := strings.ToLower(message)
+	lines := strings.Split(message, "\n")
+
+	for _, line := range lines {
+		lineLower := strings.ToLower(line)
+		line = strings.TrimSpace(line)
+
+		if strings.Contains(lineLower, "uncovered") ||
+			strings.Contains(lineLower, "not covered") ||
+			strings.Contains(lineLower, "missing coverage") ||
+			strings.Contains(lineLower, "lines not covered") {
+			if len(line) > 100 {
+				return line[:97] + "..."
+			}
+			return line
+		}
+
+		if strings.Contains(lineLower, "branch") && strings.Contains(lineLower, "not taken") {
+			if len(line) > 100 {
+				return line[:97] + "..."
+			}
+			return line
+		}
+	}
+
+	if strings.Contains(lower, "function") && strings.Contains(lower, "0%") {
+		for _, line := range lines {
+			if strings.Contains(strings.ToLower(line), "0%") && strings.Contains(line, "function") {
+				line = strings.TrimSpace(line)
+				if len(line) > 100 {
+					return line[:97] + "..."
+				}
+				return line
+			}
+		}
+	}
+
+	return ""
+}
+
+// extractErrorDetail extracts meaningful error context from task output.
+func extractErrorDetail(message string, maxLen int) string {
+	if message == "" || maxLen <= 0 {
+		return ""
+	}
+
+	lines := strings.Split(message, "\n")
+	var errorLines []string
+
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+
+		lower := strings.ToLower(line)
+
+		if strings.HasPrefix(line, "at ") && strings.Contains(line, "(") {
+			if len(errorLines) > 0 && strings.HasPrefix(strings.ToLower(errorLines[len(errorLines)-1]), "at ") {
+				continue
+			}
+		}
+
+		if strings.Contains(lower, "error") ||
+			strings.Contains(lower, "fail") ||
+			strings.Contains(lower, "exception") ||
+			strings.Contains(lower, "assert") ||
+			strings.Contains(lower, "expected") ||
+			strings.Contains(lower, "timeout") ||
+			strings.Contains(lower, "not found") ||
+			strings.Contains(lower, "cannot") ||
+			strings.Contains(lower, "undefined") ||
+			strings.HasPrefix(line, "FAIL") ||
+			strings.HasPrefix(line, "●") {
+			errorLines = append(errorLines, line)
+		}
+	}
+
+	if len(errorLines) == 0 {
+		start := len(lines) - 5
+		if start < 0 {
+			start = 0
+		}
+		for _, line := range lines[start:] {
+			line = strings.TrimSpace(line)
+			if line != "" {
+				errorLines = append(errorLines, line)
+			}
+		}
+	}
+
+	result := strings.Join(errorLines, " | ")
+	return safeTruncate(result, maxLen)
+}