modernize 37→5（-32）：interface{}→any、内置 max/min、slices/maps 辅助、strings.Cut/SplitSeq、strings.Builder（修复 mail.go O(n²) 拼接）。逐 hunk 核对语义等价；omitzero 冲突修复被自动跳过（wire 格式不变）；手动清 4 处遗留 sort import + 2 处 QF1012。

Result: {"status":"keep","total_issues":74,"golint_canonicalheader":8,"golint_errname":1,"golint_errorlint":12,"golint_forcetypeassert":3,"golint_gosec":0,"golint_intrange":3,"golint_modernize":5,"golint_nilnil":3,"golint_perfsprint":18,"golint_prealloc":3,"golint_recvcheck":7,"golint_usestdlibvars":3,"golint_wastedassign":7,"golint_total":73,"eslint_problems":1,"eslint_errors":0,"eslint_warnings":1,"tsc_errors":0,"measure_s":38}

internal/apps/edge/observability/linux.go

@@ -96,10 +96,7 @@ func ReadMemInfo() (int64, int64) {
 	if total == 0 {
 		return 0, 0
 	}
-	used := total - (memAvailableKB * 1024)
-	if used < 0 {
-		used = 0
-	}
+	used := max(total-(memAvailableKB*1024), 0)
 	return total, used
 }
 
@@ -138,8 +135,8 @@ func ReadLinuxCPUStat() (uint64, uint64) {
 	if err != nil {
 		return 0, 0
 	}
-	lines := strings.Split(string(content), "\n")
-	for _, line := range lines {
+	lines := strings.SplitSeq(string(content), "\n")
+	for line := range lines {
 		if !strings.HasPrefix(line, "cpu ") {
 			continue
 		}
@@ -260,10 +257,7 @@ func StatFilesystem(path string) (int64, int64) {
 	}
 	total := multiplyUint64Int64(stat.Blocks, stat.Bsize)
 	free := multiplyUint64Int64(stat.Bavail, stat.Bsize)
-	used := total - free
-	if used < 0 {
-		used = 0
-	}
+	used := max(total-free, 0)
 	return total, used
 }