feat(cinny-web): featured communities on Explore, matching the desktop app (#20)

chat.lotusguild.org's config.json has never had featuredCommunities, so
Explore → Featured was empty on the web while the desktop app showed the
Lotus Guild space, Homelab, Jellyfin and matrixrooms.info. Add the same
set (decided 2026-10-04).

Fixes #20

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

README.md

@@ -84,6 +84,7 @@ matrix/
 - Service: `draupnir.service`
 - Management room: `#management:matrix.lotusguild.org` (`!mEvR5fe3jMmzwd-FwNygD72OY_yu8H3UP_N-57oK7MI`)
 - Bot account: `@draupnir:matrix.lotusguild.org` (power level 100 in all protected rooms and the Lotus Guild space)
+- Encryption: off (`experimentalRustCrypto: false`), so Draupnir cannot read commands sent in the encrypted management room; send them unencrypted for now. Turning it on needs a device-bound access token first: with the current token, 2.9.0 exits with "Encryption not possible: server not revealing device ID" (tried and reverted 2026-10-16, #26 / #28).
 - Subscribed ban lists: `#community-moderation-effort-bl:neko.dev`, `#matrix-org-coc-bl:matrix.org`
 - Rebuild: `NODE_OPTIONS="--max_old_space_size=6144" npm run build`
 - Healthz endpoint: `http://10.10.10.24:8081/healthz` (200 = healthy, 418 = disconnected)
@@ -798,7 +799,7 @@ Leaving a space does **not** leave its child rooms; they are independent rooms w
 - [ ] `synchronous_commit = off` — **deliberately NOT applied.** Would be a real write-latency win, but this cluster hard-resets every few hours (HA self-fences on corosync quorum loss + the large1 DIMM), so it would drop up to ~600ms of committed messages *per reset* rather than once in a blue moon. Revisit once the cluster is stable.
 
 ### Auth & SSO
-- [x] Token-based registration
+- [x] Open registration disabled (`enable_registration: false`, 2026-10-16): accounts come from LLDAP and are created on first sign-in through Lotus SSO (Authelia OIDC, which keeps its own registration on). The old registration token was deleted.
 - [x] SSO/OIDC via Authelia
 - [x] `allow_existing_users: true` for linking accounts to SSO
 - [x] Password auth alongside SSO

cinny/config.json

@@ -8,9 +8,16 @@
   "allowCustomHomeservers": false,
   "featuredCommunities": {
     "openAsDefault": false,
-    "spaces": [],
-    "rooms": [],
-    "servers": []
+    "spaces": [
+      "!-1ZBnAH-JiCOV8MGSKN77zDGTuI3pgSdy8Unu_DrDyc",
+      "#homelab:codestorm.net"
+    ],
+    "rooms": [
+      "#jellyfin:matrix.org"
+    ],
+    "servers": [
+      "matrixrooms.info"
+    ]
   },
   "hashRouter": {
     "enabled": false,

cinny/nginx-security-headers.conf

@@ -12,4 +12,4 @@ add_header X-XSS-Protection "1; mode=block" always;
 add_header Referrer-Policy strict-origin-when-cross-origin always;
 add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
 add_header Permissions-Policy 'accelerometer=(), autoplay=(self "https://call.chat.lotusguild.org"), camera=(self "https://call.chat.lotusguild.org"), display-capture=(self "https://call.chat.lotusguild.org"), encrypted-media=(self), fullscreen=(self), geolocation=(self), gyroscope=(), magnetometer=(), microphone=(self "https://call.chat.lotusguild.org"), midi=(), payment=(), usb=()' always;
-add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' blob:; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: https://matrix.lotusguild.org https://matrix.org https://*.matrix.org https://mozilla.org https://mozilla.modular.im https://drive.lotusguild.org https://media.giphy.com https://media0.giphy.com https://media1.giphy.com https://media2.giphy.com https://media3.giphy.com https://media4.giphy.com https://www.openstreetmap.org https://tile.openstreetmap.org; font-src 'self' data:; connect-src 'self' https://matrix.lotusguild.org wss://matrix.lotusguild.org https://isitup.lotusguild.org https://matrix.org https://*.matrix.org https://mozilla.org https://mozilla.modular.im https://chat.mozilla.org https://vector.im https://api.giphy.com https://*.giphy.com wss:; media-src 'self' https: blob:; frame-src 'self' https:; worker-src 'self' blob:; object-src 'none'; frame-ancestors 'none'; base-uri 'self'; form-action 'self';" always;
+add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' blob:; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: https://matrix.lotusguild.org https://matrix.org https://*.matrix.org https://mozilla.org https://mozilla.modular.im https://drive.lotusguild.org https://media.giphy.com https://media0.giphy.com https://media1.giphy.com https://media2.giphy.com https://media3.giphy.com https://media4.giphy.com https://www.openstreetmap.org https://tile.openstreetmap.org; font-src 'self' data:; connect-src 'self' https://matrix.lotusguild.org wss://matrix.lotusguild.org https://isitup.lotusguild.org https://matrix.org https://*.matrix.org https://mozilla.org https://mozilla.modular.im https://chat.mozilla.org https://www.mozilla.org https://vector.im https://api.giphy.com https://*.giphy.com https://www.tiktok.com wss:; media-src 'self' https: blob:; frame-src 'self' https:; worker-src 'self' blob:; object-src 'none'; frame-ancestors 'none'; base-uri 'self'; form-action 'self';" always;