feat: implement Havenllo single-board kanban (Go+SQLite backend, Preact/Vite frontend)

- Single fixed 'Haven' board: lists (To do/In progress/Done) + cards, no multi-board
- Go 1.24 backend, CGO-free modernc.org/sqlite, embedded SPA, REST /api
- Preact + Vite + TS frontend, native HTML5 drag-and-drop, optimistic UI, dark Haven theme
- PVC (nfs-client) for SQLite, root container on NFS, simple nginx ingress havenllo.haven
- Dockerfile multi-arch build, Gitea CI via pipeline-actions@main

internal/store/sqlite_test.go

@@ -0,0 +1,29 @@
+package store_test
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"havenllo/internal/database"
+	"havenllo/internal/store"
+)
+
+func TestSnapshotUsesPositionOrder(t *testing.T) {
+	t.Parallel()
+	db, err := database.Open(context.Background(), filepath.Join(t.TempDir(), "havenllo.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+	if _, err := db.Exec("INSERT INTO lists (name, position) VALUES ('First', 1), ('Last', 9999)"); err != nil {
+		t.Fatal(err)
+	}
+	snapshot, err := store.Snapshot(context.Background(), db)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(snapshot.Lists) != 5 || snapshot.Lists[0].Name != "First" || snapshot.Lists[len(snapshot.Lists)-1].Name != "Last" {
+		t.Fatalf("unexpected order: %#v", snapshot.Lists)
+	}
+}