Bug 14: stream journal reads instead of buffering them; soft memory limit for the GC

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

cmd/hamlab/main.go

@@ -13,6 +13,7 @@ import (
 	"os/user"
 	"path/filepath"
 	"runtime"
+	"runtime/debug"
 	"strings"
 	"syscall"
 	"time"
@@ -171,6 +172,10 @@ func serve(cfg *config.Config) error {
 		}
 	}
 
+	// Keep the heap tidy: the daemon's live data is tens of MB; without a limit the GC
+	// happily lets RSS coast at twice that. (Soft limit: exceeding it only means more GC.)
+	debug.SetMemoryLimit(160 << 20)
+
 	col := metrics.NewCollector()
 	go col.Run(context.Background())