security: parameterize node addresses; drop dead APP_URLS config

Keeps the dev and test tooling an outside contributor would want, and takes
our node addresses out of it.

Scripts that silently defaulted to one of our nodes now require an explicit
host and exit 2 without one: smoke-test.sh, trust-archipelago-cert.sh,
dev-container-test.sh (which also derives its RPC and health URLs from the
SSH target instead of a second hardcoded copy), and image-recipe/dev-branding.sh.
A default that points at a machine the user does not own is worse than no
default: it fails confusingly, or reaches a stranger's device.

Usage examples, mock data and test fixtures move to the RFC 5737
documentation range (192.0.2.0/24). CGNAT test values stay inside
100.64.0.0/10 so the range-check semantics they exercise still hold, and
192.168.1.0/.1/.254 are left alone — those are gateway logic and UI
placeholders, not our addresses.

Playwright and the perf spec defaulted their baseURL to one of our nodes;
they now default to localhost:8100, the local dev server.

Removed neode-ui APP_URLS entirely. It is dead code — exported, never
imported — and it pinned fedimint's *prod* launch URL to 192.168.1.228:8175.
Had anything consumed it, every user's node would have tried to reach an
address that on their LAN is either nothing or someone else's machine.
Deleting beats sanitizing dead config.

Verified: frontend 868/868 vitest across 108 files; archipelago-container
75/75; mesh tests 9/9; audit-secrets 5/5. Zero node addresses and zero node
names remain in tracked files.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/dev-container-test.sh

@@ -16,10 +16,15 @@ SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
 
 SSH_KEY="${ARCHIPELAGO_SSH_KEY:-$HOME/.ssh/archipelago-deploy}"
-SSH_HOST="${ARCHIPELAGO_SSH_HOST:-archipelago@192.168.1.228}"
+SSH_HOST="${ARCHIPELAGO_SSH_HOST:-}"
+if [ -z "$SSH_HOST" ]; then
+  echo "ARCHIPELAGO_SSH_HOST must be set, e.g. archipelago@<node-host>" >&2
+  exit 2
+fi
+HOST_ONLY="${SSH_HOST#*@}"
 SSH_OPTS="-o StrictHostKeyChecking=no -o ServerAliveInterval=15 -i $SSH_KEY"
 REMOTE_DIR="/home/archipelago/archy"
-RPC_URL="http://192.168.1.228/rpc/v1"
+RPC_URL="http://${HOST_ONLY}/rpc/v1"
 COOKIE=""
 ONCE=false
 [ "$1" = "--once" ] && ONCE=true
@@ -66,7 +71,7 @@ login() {
 wait_for_health() {
     local timeout=${1:-30}
     for i in $(seq 1 "$timeout"); do
-        if curl -sf "http://192.168.1.228/health" >/dev/null 2>&1; then
+        if curl -sf "http://${HOST_ONLY}/health" >/dev/null 2>&1; then
             return 0
         fi
         sleep 1