feat: contact form backend for linux and freebsd servers

Assisted-by: GLM 5.3 Flash

internal/storage/submissions_test.go

@@ -0,0 +1,67 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+//go:build linux || freebsd
+
+package storage
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestArchiveStoreRoundTrip(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "nested", "archive-test.jsonl")
+	store := NewArchiveStore(path)
+
+	first := Submission{
+		Form:    "contact",
+		Name:    "Jane Doe",
+		Email:   "jane@example.com",
+		Service: "architecture",
+		Message: "Hello, I would like to discuss an engagement.",
+		IP:      "192.0.2.1",
+	}
+	if err := store.Append(first); err != nil {
+		t.Fatalf("append: %v", err)
+	}
+	second := Submission{Form: "feedback", Email: "other@example.com", Message: "Short"}
+	if err := store.Append(second); err != nil {
+		t.Fatalf("append: %v", err)
+	}
+
+	f, err := os.Open(path)
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	defer f.Close()
+
+	var got []Submission
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		var sub Submission
+		if err := json.Unmarshal(scanner.Bytes(), &sub); err != nil {
+			t.Fatalf("unmarshal line: %v", err)
+		}
+		got = append(got, sub)
+	}
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("scan: %v", err)
+	}
+	if len(got) != 2 {
+		t.Fatalf("lines = %d, want 2", len(got))
+	}
+	if got[0].CreatedAt.IsZero() {
+		t.Errorf("first created_at is zero, want a stamped time")
+	}
+	first.CreatedAt = got[0].CreatedAt
+	if got[0] != first {
+		t.Errorf("first = %+v, want %+v", got[0], first)
+	}
+	if got[1].CreatedAt.IsZero() {
+		t.Errorf("second created_at is zero, want a stamped time")
+	}
+}