fix(security): contain slop history writes

internal/codeguard/checks/quality/quality_ai_history.go

@@ -1,6 +1,7 @@
 package quality
 
 import (
+	"strings"
 	"time"
 
 	"github.com/devr-tools/codeguard/internal/codeguard/checks/support"
@@ -15,6 +16,11 @@ func recordSlopHistory(env support.Context, artifact *core.Artifact) {
 	if artifact == nil || artifact.SlopScore == nil {
 		return
 	}
+	// Patch validation evaluates repository-controlled content in a temporary
+	// workspace and must not persist any state to repository-configured paths.
+	if strings.TrimSpace(env.DiffText) != "" {
+		return
+	}
 	cfg := env.Config.Checks.QualityRules.AIChecks
 	if !aiCheckEnabled(cfg.SlopHistory) {
 		return

internal/codeguard/config/io.go

@@ -105,6 +105,10 @@ func containConfigArtifactPaths(cfg *core.Config, baseDir string) error {
 	if _, err := containedPath(baseDir, performanceHistoryPath); err != nil {
 		return fmt.Errorf("performance_rules.score_history: %w", err)
 	}
+	slopHistoryPath := cachefile.DerivedPath(cfg.Cache.Path, ".slop-history")
+	if _, err := containedPath(baseDir, slopHistoryPath); err != nil {
+		return fmt.Errorf("quality_rules.ai_checks.slop_history: %w", err)
+	}
 	for i := range cfg.ExternalReports {
 		resolved, err := containedPath(baseDir, cfg.ExternalReports[i].Path)
 		if err != nil {

tests/checks/quality_ai_history_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/devr-tools/codeguard/pkg/codeguard"
@@ -107,6 +108,32 @@ func TestSlopScoreHistoryHonorsToggle(t *testing.T) {
 	}
 }
 
+func TestSlopScoreHistoryDoesNotWriteDuringPatchValidation(t *testing.T) {
+	dir := t.TempDir()
+	writeSlopFixture(t, dir)
+	cfg := slopHistoryTestConfig(dir, "quality-ai-history-patch")
+	diff := strings.Join([]string{
+		"diff --git a/service.go b/service.go",
+		"index 4adc33a..59b9f08 100644",
+		"--- a/service.go",
+		"+++ b/service.go",
+		"@@ -1,5 +1,6 @@",
+		" package sample",
+		" ",
+		" func Run() error {",
+		"+\t// create error object",
+		" \terr := doThing()",
+		" \t_ = err",
+	}, "\n")
+
+	if _, err := codeguard.RunPatch(context.Background(), cfg, diff); err != nil {
+		t.Fatalf("run patch: %v", err)
+	}
+	if _, err := os.Stat(codeguard.SlopHistoryPath(cfg)); !os.IsNotExist(err) {
+		t.Fatalf("expected no history file during patch validation, stat err = %v", err)
+	}
+}
+
 func TestSlopScoreHistoryCapsEntries(t *testing.T) {
 	dir := t.TempDir()
 	writeSlopFixture(t, dir)

tests/security/config_containment_paths_test.go

@@ -121,3 +121,24 @@ func TestLoadConfigRejectsPerformanceHistorySymlinkEscape(t *testing.T) {
 		t.Fatalf("expected a performance-history symlink containment error, got %v", err)
 	}
 }
+
+func TestLoadConfigRejectsSlopHistorySymlinkEscape(t *testing.T) {
+	dir := t.TempDir()
+	outside := filepath.Join(t.TempDir(), "victim.json")
+	cacheDir := filepath.Join(dir, ".codeguard")
+	if err := os.Mkdir(cacheDir, 0o750); err != nil {
+		t.Fatalf("create cache directory: %v", err)
+	}
+	if err := os.Symlink(outside, filepath.Join(cacheDir, "cache.slop-history.json")); err != nil {
+		t.Skipf("symlinks unsupported on this platform: %v", err)
+	}
+	path := writeConfig(t, dir, ".codeguard/cache.json", "")
+
+	_, err := service.LoadConfigFile(path)
+	if err == nil {
+		t.Fatal("expected a derived slop-history symlink escape to be rejected")
+	}
+	if !strings.Contains(err.Error(), "slop_history") || !strings.Contains(err.Error(), "symlink") {
+		t.Fatalf("expected a slop-history symlink containment error, got %v", err)
+	}
+}