Architecture
============

Process model
-------------

``main.go`` loads ``.env``, reads database and port settings, opens and pings
the MySQL connection, ensures the user profile table exists, registers the
default ``net/http`` routes, and starts ``http.ListenAndServe``.

Handlers receive a shared ``*sql.DB`` through ``handlers.NewUserAPI``.
Authentication is cookie-based and sessions are held in process memory; a
restart invalidates every session.

Request domains
---------------

The handler package is split by domain:

* ``User.go`` — registration, login, profiles, account email, and user lookup;
* ``Servers.go`` and ``Channels.go`` — servers, roles, channels, invites, and
  server messages;
* ``Friends.go`` and ``Conversations.go`` — friend relationships and direct or
  group conversations;
* ``Attachments.go`` and ``Reactions.go`` — message-associated features;
* ``Websocket.go`` — live channel and conversation connections;
* ``Admin.go`` and ``Reports.go`` — account standing and moderation;
* ``Email.go`` — verification and password reset messages.

The frontend calls these handlers with ``fetch`` and opens WebSocket
connections for live message updates.