docs(readme): add app screenshots and Features section

Capture six PWA views (calendar, lists, list detail, login, setup wizard,
admin) into docs/screenshots/ and rebuild the README intro into a Features
section that expands the project description, pairing each capability with
its screenshot.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -4,12 +4,41 @@
 
 A self-hosted family organization hub for a two-person household. One color-coded calendar view across all family members' Fastmail calendars, plus shared collaborative lists (groceries, gift ideas) — delivered as a React PWA with no app store required.
 
-## What It Does
+## Features
 
-- **Unified calendar** — aggregates each member's Fastmail CalDAV calendars into a single color-coded view via tsdav + ical.js
-- **Shared lists** — collaborative grocery and gift-idea lists with live sync via Server-Sent Events
-- **PWA** — installable on iOS (Home Screen) and Android; push notifications via VAPID
-- **Single sign-on** — all auth flows through your existing Authelia OIDC deployment
+### One color-coded family calendar
+
+![FamilySync month view showing each member's events in their own color alongside shared family events](docs/screenshots/calendar.png)
+
+Every member's personal Fastmail calendars and the shared family calendar are aggregated into a single month view. Each member gets a consistent color; the shared family calendar is always rose, so anyone can tell at a glance who has what on. Events read and write straight back to Fastmail over CalDAV (tsdav + ical.js), including recurring events, all-day events, and reminders — there is no second copy of your calendar to keep in sync.
+
+### Shared collaborative lists
+
+![Lists overview showing Groceries, Gift ideas, Costco run, and Hardware store with active and completed counts](docs/screenshots/lists.png)
+
+Groceries, gift ideas, weekend errands — create as many lists as the household needs, shared with everyone or kept personal. Each card shows live active/done counts so you know what's still outstanding before you leave the house.
+
+![A grocery list detail view with checkable items, drag handles to reorder, and a completed section](docs/screenshots/list-detail.png)
+
+Inside a list, check items off, drag to reorder, and add new ones inline. Changes sync live to every other device over Server-Sent Events (with a polling fallback), so two people shopping together never duplicate or miss an item.
+
+### Single sign-on for the whole household
+
+![FamilySync sign-in screen with username and password fields plus a "Login with OIDC" option](docs/screenshots/login.png)
+
+Sign in with a local username and password, or through your existing Authelia OIDC deployment — no per-member calendar credential juggling. The PWA installs to the Home Screen on iOS and Android and supports push notifications (reminders and calendar-change alerts) via VAPID — no app store required.
+
+### Guided, zero-setup onboarding
+
+![First-run setup wizard with a four-step progress bar: Welcome, Instance, Calendar, Complete](docs/screenshots/setup.png)
+
+A first-run wizard walks the operator through configuring the instance — database, OIDC, VAPID keys, and the first Fastmail calendar connection — in about five minutes, so standing up a self-hosted instance does not require hand-editing config files.
+
+### Household administration
+
+![Admin settings showing the household members list with credential status and admin badges](docs/screenshots/admin.png)
+
+Admins manage members and their Fastmail credentials, assign each member a calendar color, choose which calendar is the shared family one, and set the household timezone — all from inside the app.
 
 ## Prerequisites