fix: replace nil context with context.TODO

internal/observability/log_test.go

@@ -0,0 +1,36 @@
+package observability
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestFormatLogEntryFormatsHTTPRequestCompactly(t *testing.T) {
+	line := formatLogEntry(LogEvent{
+		TS:    "2026-06-11T12:57:39.557972Z",
+		Level: LogLevelInfo,
+		Event: "http_request",
+		Fields: map[string]any{
+			"bytes":       56198,
+			"client_ip":   "127.0.0.1",
+			"duration_ms": 9.419,
+			"method":      "GET",
+			"path":        "/api/catalog/top-pick",
+			"status":      200,
+		},
+	})
+
+	checks := []string{
+		"2026-06-11T12:57:39.557972Z INFO http 200 GET /api/catalog/top-pick 9.419ms 54.9KB",
+	}
+
+	for _, check := range checks {
+		if !strings.Contains(line, check) {
+			t.Fatalf("line %q missing %q", line, check)
+		}
+	}
+
+	if strings.Contains(line, "client_ip=") {
+		t.Fatalf("line should omit loopback ip: %q", line)
+	}
+}