vinterliste/README.md

# Vinterliste

A small end-to-end-encrypted app for collecting *winter activities* — things to
do when winter feels long. Activities can be:

- **private** — encrypted client-side; the server only ever sees ciphertext;
- **semi-public** — visible to everyone, but the creator is **not** shown;
- **public** — visible to everyone, attributed to the creator.

See [`SECURITY.md`](./SECURITY.md) for the cryptographic model. It's load-bearing
— read it before changing anything in `shared/crypto.ts` or the auth flow.

## Stack

- **Runtime:** [Bun](https://bun.sh) 1.3+. TypeScript everywhere.
- **HTTP:** [Hono](https://hono.dev) on Bun.
- **DB:** `bun:sqlite` (built-in), WAL mode.
- **Server password hashing:** `Bun.password` (argon2id) — auth verifier only.
- **Client crypto:** `libsodium-wrappers-sumo` (WASM — the SUMO build is needed
  because the standard `libsodium-wrappers` doesn't ship `crypto_pwhash`).
  Argon2id via `crypto_pwhash`; AEAD via XChaCha20-Poly1305-IETF.
- **Frontend:** Svelte 5 + Vite. Private tag index in IndexedDB.
- **Container:** single `oven/bun` image, one volume for the SQLite file.

## Layout

```
shared/      pure modules used by both server and frontend
  crypto.ts  libsodium-backed key derivation, AEAD, wrap/unwrap, helpers
  types.ts   wire-level types shared across the network boundary

server/      Bun + Hono backend
  db.ts            bun:sqlite, WAL, idempotent schema migration
  session.ts       opaque, server-stored sessions (httpOnly cookie)
  auth.ts          signup, challenge, login, logout, password change, recovery
  activities.ts    CRUD with visibility rules
  tags.ts          server-side (public/semi) tag store + autocomplete
  index.ts         Hono app + static frontend in production

frontend/    Vite + Svelte 5 SPA
  src/lib/crypto.ts      re-exports shared/crypto for bundling
  src/lib/api.ts         fetch wrapper for the JSON API
  src/lib/auth.ts        signup/login/recovery orchestration
  src/lib/tagIndex.ts    IndexedDB store for private tags
  src/lib/session.svelte.ts  in-memory DEK + current user
  src/components/        Svelte 5 components (Login, Signup, Recovery, Home, …)

tests/       Bun tests
  crypto.test.ts   round-trip wrap/unwrap, AEAD, password change, recovery

Containerfile  single-image build for podman
```

## Running locally

You need Bun 1.3+ installed.

```bash
bun install

# 1. In one terminal — start the API on http://localhost:3000
bun run dev:server

# 2. In another terminal — start the Vite dev server on http://localhost:5173
#    (it proxies /api to :3000)
bun run dev:frontend
```

The dev server writes the SQLite file to `data/vinterliste.db`. Set
`VINTERLISTE_DB=/some/other/path` to override.

## Tests

```bash
bun test
```

The crypto tests cover:

- DEK wrap/unwrap via both the password and recovery paths;
- AEAD encrypt/decrypt round-trip, plus tamper and wrong-key rejection;
- password change preserves activity ciphertexts (DEK is the same);
- recovery unlocks even after multiple password changes;
- recovery-code normalisation handles dashes and casing;
- the safe alphabet excludes visually ambiguous characters.

## Typecheck

```bash
bun run typecheck
```

## Production build

```bash
bun run build:frontend    # produces frontend/dist
NODE_ENV=production bun run start
```

The server serves the SPA from `frontend/dist` in production. All non-`/api/*`,
non-`/assets/*` requests fall through to `index.html` so client-side routing
still works.

## Container (podman)

The provided `Containerfile` builds a single image that serves API + frontend
and persists the SQLite database in `/app/data` (one volume).

```bash
BUILDAH_FORMAT=docker podman build \
  --build-arg BUILD_DATE="$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
  --build-arg GIT_REVISION="$(git describe --always --dirty 2>/dev/null || echo dev)" \
  -t vinterliste:latest .

# Create a named volume for the SQLite file
podman volume create vinterliste-data

podman run --replace --name vinterliste \
  -p 3000:3000 \
  -v vinterliste-data:/app/data:Z \
  vinterliste:latest

# Visit http://localhost:3000
```

The container exposes `/api/health` for healthchecks and bakes the build date /
git revision into both OCI labels and `/etc/build-info`.

## Installable (PWA) + mobile

The SPA ships with a web app manifest (`/manifest.webmanifest`), an SVG icon
(`/icon.svg`), and a small service worker (`/sw.js`) that caches the bundled
shell for offline reads. The API itself is **never** cached — sessions and
ciphertexts must come fresh from the server. On supported browsers
(Chrome/Edge on Android and desktop, Firefox with the flag) you'll see an
"Install" prompt; on iOS you can Add to Home Screen but iOS doesn't render
SVG icons, so the home-screen icon will fall back to the page screenshot.

Layout adapts to small screens via:

- `viewport` set to `width=device-width, initial-scale=1, viewport-fit=cover`
- safe-area insets in `padding` so content doesn't slip under iOS notches
- `min-height: 44px` on buttons (WCAG 2.5.5 enhanced touch target)
- `font-size: 16px` on inputs below 480px so iOS doesn't auto-zoom

## Promoting a moderator

Moderators can delete any `semi` or `public` activity (not `private` — those
aren't visible to anyone else anyway). There's no admin UI; promotion is a
one-liner against the SQLite file:

```bash
sqlite3 data/vinterliste.db \
  "UPDATE users SET is_moderator = 1 WHERE email = 'olemd@example.org';"
```

The user has to log out and back in for `MeResponse.is_moderator` to refresh.

## Manual verification

After signing up an account, the spec asks you to inspect a `private` row
directly in the DB and confirm only ciphertext is stored:

```bash
sqlite3 data/vinterliste.db \
  "SELECT id, visibility, title, loc_label, scheduled_at,
          length(ciphertext) AS ct_len, length(nonce) AS nc_len
   FROM activities WHERE visibility = 'private';"
```

You should see `title`, `loc_label`, and `scheduled_at` all `NULL`, and the
`ciphertext` / `nonce` columns populated.

## Status / scope

This is the scaffold from `winter-list-claude-code-prompt.md`. In scope:

- repo structure, schema, single-image container
- crypto module + tests
- signup / login / password change / recovery
- activity CRUD with strict visibility handling
- tag autocomplete (server `tags` table + client IndexedDB)

Explicitly **out of scope** for now:

- sharing/permissions beyond the three visibility levels
- comments, notifications, other social features
- native/mobile apps
- server-side full-text search over private data
- rate limiting on auth/recovery endpoints (defense-in-depth — the recovery
  verifier already closes the lockout-DoS hole; rate limiting reduces online
  brute-force surface)