chore: remove unused Redis service and references (#26)

CLAUDE.md

@@ -11,7 +11,6 @@ FamilySync is a self-hosted, Dockerized family organization hub for a two-person
 ### Constraints
 
 - **Tech stack**: MariaDB for the database — PostgreSQL is not available in the stack
-- **Tech stack**: Redis available (optional, for live list sync / push)
 - **Infrastructure**: Unraid host running Docker + Docker Compose
 - **Auth**: Authelia (already deployed) + Local Auth — OIDC/OAuth2 for the custom app; all members authenticate through it
 - **Calendar backend**: Fastmail (paid, existing) is the single source for all calendars via JMAP/CalDAV
@@ -50,7 +49,6 @@ FamilySync is a self-hosted, Dockerized family organization hub for a two-person
 | web-push              | 3.6.7   | Server-side VAPID push           | Generate VAPID keys, sign and dispatch push messages to browser push services (APNs for iOS, FCM for Android)                                 |
 | @hono/oidc-auth       | 1.8.3   | OIDC session middleware for Hono | Storage-less JWT session cookies; authorization-code + PKCE flow; works with any RFC-compliant OIDC provider including Authelia               |
 | openid-client         | 6.8.4   | Low-level OIDC primitives        | If `@hono/oidc-auth` proves insufficient (e.g., custom token introspection), use this as the lower-level escape hatch                         |
-| ioredis               | 5.11.0  | Redis client                     | Pub/sub for broadcasting list-change events to SSE connections across Node processes                                                          |
 | zod                   | 3.24.x  | Schema validation                | Validate API request bodies and CalDAV event payloads before writing back to Fastmail                                                         |
 | @hono/zod-validator   | 0.8.0   | Hono middleware for Zod          | Validate request body/query in route handlers with Zod schemas                                                                                |
 | @tanstack/react-query | 5.101.0 | Server state + caching           | Manages calendar and list data fetching, background refetch, stale-while-revalidate; pairs with SSE for live list updates                     |
@@ -199,7 +197,7 @@ The backend handles two auth paths: local username/password (scrypt + HS256 JWT
 
 Calendar data lives exclusively in Fastmail CalDAV. The broker layer (`apps/api/src/broker/`) uses `tsdav` for PROPFIND/REPORT/PUT/DELETE, `ical.js` for VCALENDAR parsing, and `rrule` for server-side recurrence expansion. Writes are enqueued in a `calendarOutbox` table and drained asynchronously every 15 seconds; a ctag-based poller re-syncs calendars every 5 minutes.
 
-Lists are persisted in MariaDB. Live list updates flow over SSE (`text/event-stream`) via an in-process Node.js `EventEmitter`; a 30-second polling fallback is always active. Push notifications (reminders + calendar change alerts) are dispatched via `web-push` (VAPID) to APNs/FCM. Redis is present in the stack but not yet used at runtime (reserved for future multi-process pub/sub).
+Lists are persisted in MariaDB. Live list updates flow over SSE (`text/event-stream`) via an in-process Node.js `EventEmitter`; a 30-second polling fallback is always active. Push notifications (reminders + calendar change alerts) are dispatched via `web-push` (VAPID) to APNs/FCM.
 
 The PWA uses TanStack Query for all server state (events, lists, user, sync status, auth mode) and Zustand for UI-only state (selected date, open panels, active tab).
 
@@ -221,7 +219,7 @@ familysync/
 │       ├── hooks/           # useListSSE, usePushSubscription
 │       ├── store/           # Zustand stores (calendarStore, listsStore)
 │       └── sw.ts            # Custom Workbox service worker
-├── docker-compose.yml       # Production stack (api + mariadb + redis)
+├── docker-compose.yml       # Production stack (api + mariadb)
 └── docker-compose.dev.yml   # Dev overrides
 ```