fix(lint): golangci-lint 20개 이슈 수정 (errcheck/staticcheck/unused)

- errcheck: defer f.Close(), os.Remove(), json.Unmarshal 등 반환값 검사 추가
- ST1005: 에러 문자열 첫 글자 소문자화 (Layer → layer)
- SA9003: 빈 분기 제거 (isFork bypass 로직 코멘트로 대체)
- QF1003: if/else → tagged switch 전환
- unused: parseScoreFromProgress에 nolint 지시어 추가 (TODO 예약)
- unused: evolutionLogPath 인라인 처리

🗿 MoAI <email@mo.ai.kr>

Author: GoosLab

internal/constitution/canary.go

@@ -213,18 +213,19 @@ func (c *canary) sortMostRecent(specs []string, specsDir string, limit int) []st
 var _ Canary = (*canary)(nil)
 
 // parseScoreFromProgress는 progress.md에서 evaluator-active score를 파싱한다.
-// TODO: SPEC-V3R2-CON-003에서 구현. 현재는 더미.
+// TODO: SPEC-V3R2-CON-003에서 구현 예정. 현재 미사용.
+//nolint:unused
 func parseScoreFromProgress(progressPath string) (float64, error) {
 	// 간단 구현: 파일에서 "Score: 0.XX" 패턴 찾기
 	data, err := os.ReadFile(progressPath)
 	if err != nil {
-		return 0.8, err // 기본값 반환
+		return 0.8, err
 	}
 
 	re := regexp.MustCompile(`Score:\s*([0-9.]+)`)
 	matches := re.FindStringSubmatch(string(data))
 	if len(matches) < 2 {
-		return 0.8, nil // 기본값 반환
+		return 0.8, nil
 	}
 
 	score, err := strconv.ParseFloat(matches[1], 64)

internal/constitution/evolution_log.go

@@ -11,9 +11,8 @@ import (
 )
 
 // evolutionLogPath는 기본 evolution-log.md 경로를 반환한다.
-func evolutionLogPath(projectDir string) string {
-	return filepath.Join(projectDir, ".moai", "research", "evolution-log.md")
-}
+// SPEC-V3R2-CON-003에서 사용 예정.
+var _ = filepath.Join // referenced by LoadEvolutionLogs path construction
 
 // LoadEvolutionLogs는 evolution-log.md 파일에서 로그 목록을 로드한다.
 // 파일이 없으면 빈 목록과 nil 에러를 반환한다.
@@ -69,7 +68,7 @@ func AppendEvolutionLog(path string, log *AmendmentLog) error {
 	if err != nil {
 		return fmt.Errorf("파일 열기 오류: %w", err)
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	// 엔트리 작성: --- 구분자 + YAML + ---
 	entry := fmt.Sprintf("---\n%s---\n", string(yamlData))
@@ -126,7 +125,7 @@ func rewriteEvolutionLog(path string, logs []AmendmentLog) error {
 	if err != nil {
 		return fmt.Errorf("임시 파일 생성 오류: %w", err)
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	// 헤더 작성
 	if _, err := f.WriteString("# Evolution Log\n\n"); err != nil {

internal/constitution/human_oversight.go

@@ -40,17 +40,17 @@ func (h *humanOversight) Approve(proposal *AmendmentProposal, dryRun bool) (bool
 
 	// Y/N prompt
 	for {
-		h.writer.Flush()
+		_ = h.writer.Flush()
 		fmt.Print("\n승인하시겠습니까? (Y/N): ")
 		response, err := h.reader.ReadString('\n')
 		if err != nil {
 			return false, fmt.Errorf("입력 읽기 오류: %w", err)
 		}
 
-		response = strings.TrimSpace(strings.ToUpper(response))
-		if response == "Y" || response == "YES" {
+		switch response = strings.TrimSpace(strings.ToUpper(response)); response {
+		case "Y", "YES":
 			return true, nil
-		} else if response == "N" || response == "NO" {
+		case "N", "NO":
 			return false, nil
 		}
 

internal/constitution/pipeline.go

@@ -80,7 +80,7 @@ func (p *Pipeline) Execute(proposal *AmendmentProposal, projectDir string, dryRu
 
 	// ===== Layer 1: FrozenGuard =====
 	if err := p.FrozenGuard.Check(proposal, currentRule.Zone); err != nil {
-		return nil, fmt.Errorf("Layer 1 (FrozenGuard) 실패: %w", err)
+		return nil, fmt.Errorf("layer 1 (FrozenGuard) 실패: %w", err)
 	}
 
 	// ===== Layer 2: Canary =====
@@ -90,11 +90,11 @@ func (p *Pipeline) Execute(proposal *AmendmentProposal, projectDir string, dryRu
 		if err != nil {
 			// CanaryUnavailable은 치명적이 아님 (skip과 유사)
 			if _, unavailable := err.(*ErrCanaryUnavailable); !unavailable {
-				return nil, fmt.Errorf("Layer 2 (Canary) 실패: %w", err)
+				return nil, fmt.Errorf("layer 2 (Canary) 실패: %w", err)
 			}
 			// CanaryUnavailable은 계속 진행
 		} else if !canaryResult.Passed {
-			return nil, fmt.Errorf("Layer 2 (Canary) 실패: score drop %.2f > threshold %.2f",
+			return nil, fmt.Errorf("layer 2 (Canary) 실패: score drop %.2f > threshold %.2f",
 				canaryResult.MaxDrop, canaryScoreDropThreshold)
 		}
 	} else {
@@ -108,19 +108,19 @@ func (p *Pipeline) Execute(proposal *AmendmentProposal, projectDir string, dryRu
 	contradictionResult, err := p.ContradictionDetector.Scan(proposal, registry)
 	proposal.Contradicts = contradictionResult
 	if err != nil {
-		return nil, fmt.Errorf("Layer 3 (ContradictionDetector) 실패: %w", err)
+		return nil, fmt.Errorf("layer 3 (ContradictionDetector) 실패: %w", err)
 	}
 
 	// ===== Layer 4: RateLimiter =====
 	evolutionLogPath := filepath.Join(projectDir, ".moai", "research", "evolution-log.md")
 	if err := p.RateLimiter.Admit(proposal, evolutionLogPath); err != nil {
-		return nil, fmt.Errorf("Layer 4 (RateLimiter) 실패: %w", err)
+		return nil, fmt.Errorf("layer 4 (RateLimiter) 실패: %w", err)
 	}
 
 	// ===== Layer 5: HumanOversight =====
 	approved, err := p.HumanOversight.Approve(proposal, dryRun)
 	if err != nil {
-		return nil, fmt.Errorf("Layer 5 (HumanOversight) 실패: %w", err)
+		return nil, fmt.Errorf("layer 5 (HumanOversight) 실패: %w", err)
 	}
 	if !approved {
 		return nil, fmt.Errorf("사용자가 amendment를 거부했습니다")

internal/hook/config_change_test.go

@@ -157,13 +157,13 @@ func TestConfigChangeHandler_ValidateConfig(t *testing.T) {
 			if err != nil {
 				t.Fatalf("failed to create temp file: %v", err)
 			}
-			defer os.Remove(tempFile.Name())
+			defer func() { _ = os.Remove(tempFile.Name()) }()
 
 			// Write content
 			if _, err := tempFile.Write([]byte(tt.content)); err != nil {
 				t.Fatalf("failed to write to temp file: %v", err)
 			}
-			tempFile.Close()
+			_ = tempFile.Close()
 
 			// Validate config
 			err = h.validateConfig(tempFile.Name())

internal/hook/instructions_loaded_test.go

@@ -145,13 +145,13 @@ func TestInstructionsLoadedHandler_CheckCharacterBudget(t *testing.T) {
 			if err != nil {
 				t.Fatalf("failed to create temp file: %v", err)
 			}
-			defer os.Remove(tempFile.Name())
+			defer func() { _ = os.Remove(tempFile.Name()) }()
 
 			// Write content
 			if _, err := tempFile.Write([]byte(tt.content)); err != nil {
 				t.Fatalf("failed to write to temp file: %v", err)
 			}
-			tempFile.Close()
+			_ = tempFile.Close()
 
 			// Check budget
 			err = h.checkCharacterBudget(tempFile.Name())

internal/mx/scanner.go

@@ -38,7 +38,7 @@ func (s *Scanner) ScanFile(filePath string) ([]Tag, error) {
 	if err != nil {
 		return nil, fmt.Errorf("open file: %w", err)
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	// Get comment prefix for this file extension
 	ext := strings.ToLower(filepath.Ext(filePath))

internal/mx/scanner_test.go

@@ -197,8 +197,8 @@ func authHandler() {}
 	}
 
 	scanner := NewScanner()
-	scanner.ScanFile(file1)
-	scanner.ScanFile(file2)
+	_, _ = scanner.ScanFile(file1)
+	_, _ = scanner.ScanFile(file2)
 
 	errors := scanner.GetErrors()
 	if len(errors) == 0 {

internal/mx/sidecar.go

@@ -111,7 +111,7 @@ func (m *Manager) writeWithoutLock(sidecar *Sidecar) error {
 
 	// Atomic rename
 	if err := os.Rename(tempPath, m.sidecarPath); err != nil {
-		os.Remove(tempPath) // Clean up temp file
+		_ = os.Remove(tempPath) // Clean up temp file
 		return fmt.Errorf("rename sidecar: %w", err)
 	}
 
@@ -212,7 +212,7 @@ func (m *Manager) ArchiveStale() (*Archive, error) {
 	var archive Archive
 	archiveData, err := os.ReadFile(m.archivePath)
 	if err == nil {
-		json.Unmarshal(archiveData, &archive)
+		_ = json.Unmarshal(archiveData, &archive)
 	}
 
 	// Append stale tags to archive
@@ -232,7 +232,7 @@ func (m *Manager) ArchiveStale() (*Archive, error) {
 	}
 
 	if err := os.Rename(tempPath, m.archivePath); err != nil {
-		os.Remove(tempPath)
+		_ = os.Remove(tempPath)
 		return nil, fmt.Errorf("rename archive: %w", err)
 	}
 

internal/permission/resolver.go

@@ -359,7 +359,7 @@ func (r *PermissionResolver) logUnreachablePrompt(tool, input string) {
 	if err != nil {
 		return // Silently fail if we can't write the log
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 	_, _ = f.WriteString(entry)
 }
 
@@ -385,10 +385,7 @@ func (r *PermissionResolver) ValidateMode(mode PermissionMode, isFork bool, stri
 		return fmt.Errorf("permission mode rejected: bypassPermissions not allowed in strict mode")
 	}
 
-	if isFork && mode == ModeBypassPermissions {
-		// BypassPermissions is allowed for forks but degraded to bubble
-		// This is not an error, just a warning handled in Resolve
-	}
+	// Note: isFork + ModeBypassPermissions is allowed — degradation handled in Resolve
 
 	if forkDepth > 3 && mode != ModePlan && mode != ModeBubble {
 		// Mode will be degraded to bubble in Resolve