feat(cuprate-ui): companion dashboard for the Cuprate Monero node

Same companion shape as bitcoin-ui/electrs-ui: host-networked nginx
bound to 127.0.0.1:18091 (auth: gated + session_passthrough), serving
a dark glass status page that polls the node's restricted RPC via a
session-gated /cuprate-rpc/ proxy — sync height/target with progress
bar, peers, mempool, chain size and free disk (from get_info), plus a
wallet 'remote node' endpoint. The offline state explains the disk gate
so a refused node says why.

No secret rendering: the restricted RPC is Monero's safe-for-public
subset, so nginx.conf is baked into the image (no pre_start hook, no
bind mount). companion.rs auto-provisions archy-cuprate-ui alongside
cuprate and reaps it when cuprate goes.

Catalog regenerated (cuprate-ui entry + manifest embed, 18091 into the
mesh launch-port list). NOTE: releases/app-catalog.json is UNSIGNED as
committed — run scripts/sign-catalog.sh before publishing.

core/archipelago/src/fips/app_ports.rs

@@ -6,7 +6,41 @@
 //! no listener, so allowing them is inert.
 
 pub const APP_LAUNCH_PORTS: &[u16] = &[
-    2283, 2342, 3000, 3001, 3002, 3030, 4080, 5180, 7778, 8080, 8081, 8082, 8083, 8084, 8085, 8087,
-    8090, 8096, 8123, 8175, 8176, 8187, 8240, 8334, 8336, 8888, 8999, 9000, 9100, 10380, 11434,
-    18081, 18083, 23000, 32838, 50002,
+    2283,
+    2342,
+    3000,
+    3001,
+    3002,
+    3030,
+    4080,
+    5180,
+    7778,
+    8080,
+    8081,
+    8082,
+    8083,
+    8084,
+    8085,
+    8087,
+    8090,
+    8096,
+    8123,
+    8175,
+    8176,
+    8187,
+    8240,
+    8334,
+    8336,
+    8888,
+    8999,
+    9000,
+    9100,
+    10380,
+    11434,
+    18081,
+    18083,
+    18091,
+    23000,
+    32838,
+    50002,
 ];