/**
 * # gerbeur
 *
 * A small invite-only social platform for sharing links and files. The
 * repository holds three parts: the backend in `api/`, the frontend in `src/`,
 * and in `shared/` whatever crosses the wire between them. This reference
 * documents the backend and the shared modules; the frontend isn't in it yet.
 *
 * ## Backend — `api/`
 *
 * An Oak server over SQLite that answers the API and the WebSocket, and serves
 * the built frontend. A request goes through a route, which parses it and
 * answers. The route calls services, which hold the logic and every SQL query;
 * they read rows through the model, and reach other sites only through
 * `remote/`.
 *
 * - **Entry point** — builds the application and listens:
 *   [main](./api/main.ts/index.html).
 * - **Routes** — the HTTP API; each router's page lists its endpoints:
 *   [attachments](./api/routes/attachments.ts/index.html),
 *   [avatars](./api/routes/avatars.ts/index.html),
 *   [bandcamp](./api/routes/bandcamp.ts/index.html),
 *   [categories](./api/routes/categories.ts/index.html),
 *   [chat](./api/routes/chat.ts/index.html),
 *   [comments](./api/routes/comments.ts/index.html),
 *   [dumps](./api/routes/dumps.ts/index.html),
 *   [files](./api/routes/files.ts/index.html),
 *   [follows](./api/routes/follows.ts/index.html),
 *   [invites](./api/routes/invites.ts/index.html),
 *   [notifications](./api/routes/notifications.ts/index.html),
 *   [playlists](./api/routes/playlists.ts/index.html),
 *   [preview](./api/routes/preview.ts/index.html),
 *   [search](./api/routes/search.ts/index.html),
 *   [thumbnails](./api/routes/thumbnails.ts/index.html),
 *   [users](./api/routes/users.ts/index.html),
 *   [ws](./api/routes/ws.ts/index.html),
 *   [youtube](./api/routes/youtube.ts/index.html).
 * - **Middleware** — what runs around every route:
 *   [auth](./api/middleware/auth.ts/index.html),
 *   [error](./api/middleware/error.ts/index.html),
 *   [og](./api/middleware/og.ts/index.html).
 * - **Services** — the logic and every SQL query, one module per domain:
 *   [attachment-service](./api/services/attachment-service.ts/index.html),
 *   [backlink-service](./api/services/backlink-service.ts/index.html),
 *   [category-service](./api/services/category-service.ts/index.html),
 *   [chat-service](./api/services/chat-service.ts/index.html),
 *   [comment-like-service](./api/services/comment-like-service.ts/index.html),
 *   [comment-service](./api/services/comment-service.ts/index.html),
 *   [dump-service](./api/services/dump-service.ts/index.html),
 *   [email-service](./api/services/email-service.ts/index.html),
 *   [follow-service](./api/services/follow-service.ts/index.html),
 *   [invite-service](./api/services/invite-service.ts/index.html),
 *   [notification-service](./api/services/notification-service.ts/index.html),
 *   [password-reset-service](./api/services/password-reset-service.ts/index.html),
 *   [playlist-service](./api/services/playlist-service.ts/index.html),
 *   [rich-content-service](./api/services/rich-content-service.ts/index.html),
 *   [user-service](./api/services/user-service.ts/index.html),
 *   [vote-service](./api/services/vote-service.ts/index.html),
 *   [ws-service](./api/services/ws-service.ts/index.html).
 * - **Model** — per table, its row type, guard and mappers:
 *   [auth](./api/model/auth.ts/index.html),
 *   [category](./api/model/category.ts/index.html),
 *   [chat](./api/model/chat.ts/index.html),
 *   [comment](./api/model/comment.ts/index.html),
 *   [dump](./api/model/dump.ts/index.html),
 *   [follow](./api/model/follow.ts/index.html),
 *   [invite](./api/model/invite.ts/index.html),
 *   [notification](./api/model/notification.ts/index.html),
 *   [password-reset](./api/model/password-reset.ts/index.html),
 *   [playlist](./api/model/playlist.ts/index.html),
 *   [user](./api/model/user.ts/index.html).
 * - **Validators** — the request-body guards:
 *   [category](./api/validators/category.ts/index.html),
 *   [comment](./api/validators/comment.ts/index.html),
 *   [dump](./api/validators/dump.ts/index.html),
 *   [playlist](./api/validators/playlist.ts/index.html),
 *   [user](./api/validators/user.ts/index.html).
 * - **Remote** — the only place that fetches from other sites:
 *   [bandcamp-streams](./api/remote/bandcamp-streams.ts/index.html),
 *   [bandcamp-tralbum](./api/remote/bandcamp-tralbum.ts/index.html),
 *   [fetch](./api/remote/fetch.ts/index.html),
 *   [html](./api/remote/html.ts/index.html),
 *   [image-proxy](./api/remote/image-proxy.ts/index.html),
 *   [public-address](./api/remote/public-address.ts/index.html),
 *   [twemoji](./api/remote/twemoji.ts/index.html),
 *   [youtube-playlist](./api/remote/youtube-playlist.ts/index.html).
 * - **Link providers** — the previews of each kind of site:
 *   [bandcamp](./api/remote/providers/bandcamp.ts/index.html),
 *   [generic](./api/remote/providers/generic.ts/index.html),
 *   [provider](./api/remote/providers/provider.ts/index.html),
 *   [self](./api/remote/providers/self.ts/index.html),
 *   [soundcloud](./api/remote/providers/soundcloud.ts/index.html),
 *   [youtube](./api/remote/providers/youtube.ts/index.html).
 * - **Lib** — helpers that belong to no layer:
 *   [api-exception](./api/lib/api-exception.ts/index.html),
 *   [auth](./api/lib/auth.ts/index.html),
 *   [canonical-url](./api/lib/canonical-url.ts/index.html),
 *   [index-html](./api/lib/index-html.ts/index.html),
 *   [jwt](./api/lib/jwt.ts/index.html),
 *   [pagination](./api/lib/pagination.ts/index.html),
 *   [permissions](./api/lib/permissions.ts/index.html),
 *   [playlist-members](./api/lib/playlist-members.ts/index.html),
 *   [rate-limit](./api/lib/rate-limit.ts/index.html),
 *   [reserved-slugs](./api/lib/reserved-slugs.ts/index.html),
 *   [self-url](./api/lib/self-url.ts/index.html),
 *   [serve-file](./api/lib/serve-file.ts/index.html),
 *   [site-icons](./api/lib/site-icons.ts/index.html),
 *   [slugify](./api/lib/slugify.ts/index.html),
 *   [static](./api/lib/static.ts/index.html),
 *   [upload](./api/lib/upload.ts/index.html).
 * - **Database** — the handle, its creation, migration and startup
 *   housekeeping: [connection](./api/db/connection.ts/index.html),
 *   [init](./api/db/init.ts/index.html),
 *   [migrate](./api/db/migrate.ts/index.html),
 *   [startup](./api/db/startup.ts/index.html).
 * - **Migrations** — applied in order, each once:
 *   [0001_comment_likes](./api/db/migrations/0001_comment_likes.ts/index.html),
 *   [0002_dump_thumbnail](./api/db/migrations/0002_dump_thumbnail.ts/index.html),
 *   [0003_dump_backlinks](./api/db/migrations/0003_dump_backlinks.ts/index.html),
 *   [0004_user_roles](./api/db/migrations/0004_user_roles.ts/index.html),
 *   [0005_drop_is_admin](./api/db/migrations/0005_drop_is_admin.ts/index.html),
 *   [0006_categories](./api/db/migrations/0006_categories.ts/index.html),
 *   [0007_password_reset_tokens](./api/db/migrations/0007_password_reset_tokens.ts/index.html),
 *   [0008_chat_messages](./api/db/migrations/0008_chat_messages.ts/index.html),
 *   [0009_chat_reply](./api/db/migrations/0009_chat_reply.ts/index.html),
 *   [0010_youtube_embed_start](./api/db/migrations/0010_youtube_embed_start.ts/index.html),
 *   [0011_split_favicon_thumbnail](./api/db/migrations/0011_split_favicon_thumbnail.ts/index.html),
 *   [0012_fix_favicon_reclassification](./api/db/migrations/0012_fix_favicon_reclassification.ts/index.html),
 *   [0013_dump_url_canonical](./api/db/migrations/0013_dump_url_canonical.ts/index.html),
 *   [0014_chat_read_state](./api/db/migrations/0014_chat_read_state.ts/index.html),
 *   [0015_token_revocation](./api/db/migrations/0015_token_revocation.ts/index.html),
 *   [0016_performance_indexes](./api/db/migrations/0016_performance_indexes.ts/index.html).
 * - **Settings and scripts**: [config](./api/config.ts/index.html),
 *   [generate-icons](./api/scripts/generate-icons.ts/index.html).
 *
 * ## Shared — `shared/`
 *
 * The types and constants both halves use: the API envelope, each domain's
 * types and request bodies, the socket protocol, the validation limits and the
 * role permissions. It imports nothing from either half.
 *
 * Modules: [api](./shared/api.ts/index.html),
 * [category](./shared/category.ts/index.html),
 * [chat](./shared/chat.ts/index.html),
 * [comment](./shared/comment.ts/index.html),
 * [dump](./shared/dump.ts/index.html), [follow](./shared/follow.ts/index.html),
 * [mention](./shared/mention.ts/index.html),
 * [notification](./shared/notification.ts/index.html),
 * [permissions](./shared/permissions.ts/index.html),
 * [player](./shared/player.ts/index.html),
 * [playlist](./shared/playlist.ts/index.html),
 * [search](./shared/search.ts/index.html), [user](./shared/user.ts/index.html),
 * [validation](./shared/validation.ts/index.html),
 * [ws](./shared/ws.ts/index.html).
 *
 * ## Frontend — `src/`
 *
 * The React app, built with Vite. Not in this reference yet.
 *
 * @module
 */