feat: initialize warpbox.dev project structure and backend

Initialize the repository with the core Go backend architecture and a frontend mockup for warpbox.dev, a self-hosted file-sharing application.

- Set up Go backend modules for configuration, HTTP server, middleware, handlers, and templates.
- Add local development scripts, environment templates, and basic project configuration.
- Include a React-based frontend mockup under the docs directory.

backend/libs/config/config_test.go

@@ -0,0 +1,34 @@
+package config
+
+import "testing"
+
+func TestParseMegabytes(t *testing.T) {
+	tests := map[string]int64{
+		"0.5":   512 * 1024,
+		"0.5Mb": 512 * 1024,
+		"1mb":   1024 * 1024,
+		"1MB":   1024 * 1024,
+		"1.5Mb": 1536 * 1024,
+		" 2 ":   2 * 1024 * 1024,
+	}
+
+	for input, want := range tests {
+		got, err := parseMegabytes(input)
+		if err != nil {
+			t.Fatalf("parseMegabytes(%q) returned error: %v", input, err)
+		}
+		if got != want {
+			t.Fatalf("parseMegabytes(%q) = %d, want %d", input, got, want)
+		}
+	}
+}
+
+func TestParseMegabytesRejectsInvalidValues(t *testing.T) {
+	tests := []string{"", "0", "-1", "abc"}
+
+	for _, input := range tests {
+		if _, err := parseMegabytes(input); err == nil {
+			t.Fatalf("parseMegabytes(%q) returned nil error", input)
+		}
+	}
+}