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.

docs/Mock-Up/Mockup Magic/.lovable/project.json

@@ -0,0 +1,4 @@
+{
+  "schemaVersion": 1,
+  "template": "tanstack_start_ts_2026-05-12"
+}