review(lifecycle): drop double-truncation of persisted hook output

stdoutBuf and stderrBuf are each lifecycleCappedBuffer-backed and
already append "\n...<truncated>" when they hit
lifecycleMaxOutputBytes, so the combined string is already bounded.
The outer truncateLifecycleOutputInternal call sliced at a fixed
byte boundary, which could land mid-UTF-8 codepoint and corrupt the
persisted output. Drop the call (and the now-unused helper + its
test); rely on the buffers.

The combined ceiling is now ~2× lifecycleMaxOutputBytes (stdout +
separator + stderr) which is fine — pre_deploy_last_run_output is
TEXT in both Postgres and SQLite.

Greptile review on getarcaneapp#2782.

Author: peitschie

backend/internal/services/lifecycle_service.go

@@ -173,7 +173,11 @@ func (s *LifecycleService) executePreDeployInternal(ctx context.Context, project
 	durationMs := time.Since(start).Milliseconds()
 
 	status := lifecycleStatusForResultInternal(exitCode, runErr)
-	persistedOutput := truncateLifecycleOutputInternal(combineLifecycleOutputInternal(stdoutContent, stderrContent), lifecycleMaxOutputBytes)
+	// stdoutBuf/stderrBuf already enforce lifecycleMaxOutputBytes each with a
+	// proper "...<truncated>" marker, so the combined string is already
+	// bounded and we don't slice again here — a second byte-boundary cut
+	// could land mid-UTF-8 codepoint and produce garbled output.
+	persistedOutput := combineLifecycleOutputInternal(stdoutContent, stderrContent)
 	s.persistLastRunInternal(ctx, sync.ID, status, persistedOutput, start)
 	s.emitLifecycleEventInternal(ctx, project, sync, status, exitCode, durationMs, runErr, actor)
 
@@ -673,13 +677,6 @@ func combineLifecycleOutputInternal(stdout, stderr string) string {
 	}
 }
 
-func truncateLifecycleOutputInternal(content string, maxBytes int) string {
-	if maxBytes <= 0 || len(content) <= maxBytes {
-		return content
-	}
-	return content[:maxBytes] + "\n...<truncated>"
-}
-
 func removeLifecycleContainerInternal(ctx context.Context, dockerClient *client.Client, containerID string, apiTimeoutSec int) {
 	if dockerClient == nil || containerID == "" {
 		return

backend/internal/services/lifecycle_service_test.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 	"time"
 
@@ -218,16 +217,6 @@ func TestCombineLifecycleOutput(t *testing.T) {
 	}
 }
 
-func TestTruncateLifecycleOutput(t *testing.T) {
-	short := "hello"
-	assert.Equal(t, short, truncateLifecycleOutputInternal(short, 1024))
-
-	long := strings.Repeat("a", 200)
-	got := truncateLifecycleOutputInternal(long, 100)
-	require.True(t, strings.HasPrefix(got, strings.Repeat("a", 100)))
-	require.Contains(t, got, "<truncated>")
-}
-
 func TestRunPreDeploy_NilProject(t *testing.T) {
 	db := setupLifecycleTestDB(t)
 	svc, _ := newLifecycleTestService(t, db)