feat(admin): apix-admin UI at admin.api-index.org

Internal maintainer dashboard: global stats, sandbox list with
tier-filter and pagination, sandbox drill-down with D3 world map,
tier-promotion form. API-key auth via HttpOnly cookie. Port 8084,
rolling a/b deploy alongside the existing service pairs.

- apix-common: AdminSandboxSummary, AdminSandboxListResponse, AdminStatsResponse DTOs
- apix-registry: AdminResource (4 endpoints), SandboxService.listAllSandboxes + getGlobalStats
- apix-registry: SandboxResource GET /{uuid}/dashboard endpoint (was missing — fixes portal 500)
- apix-portal: RegistryClient path corrected to /dashboard
- apix-admin: new Quarkus module — auth filter, registry REST client, 3 resources, 6 Qute templates, admin.js
- infra: Dockerfile.admin, docker-compose admin-a/b services, Caddyfile admin.api-index.org block
- scripts: deploy-bluegreen.sh extended for admin-a/b

Co-Authored-By: Mira Rehfeld <noreply@anthropic.com>

scripts/reset.sh

@@ -11,6 +11,12 @@ info() { echo -e "${GREEN}[apix]${NC} $*"; }
 warn() { echo -e "${YELLOW}[warn]${NC} $*"; }
 die()  { echo -e "${RED}[fail]${NC} $*" >&2; exit 1; }
 
+_on_exit() {
+  echo ""
+  read -rp "Press Enter to close…" _
+}
+trap _on_exit EXIT
+
 warn "This will DROP and recreate the local 'apix' database."
 read -rp "Continue? [y/N] " confirm
 [[ "${confirm,,}" == "y" ]] || { echo "Aborted."; exit 0; }
@@ -58,12 +64,5 @@ for i in $(seq 1 30); do
   sleep 1
 done
 
-info "Running Liquibase migrations"
-mvn -q liquibase:update -pl apix-registry \
-  -Dliquibase.url="jdbc:postgresql://localhost:${DB_PORT}/${DB_NAME}" \
-  -Dliquibase.username="$DB_USER" \
-  -Dliquibase.password="$DB_PASS"
-info "Migrations applied"
-
-info "Reset complete — starting dev servers"
-"$SCRIPT_DIR/dev.sh"
+info "Reset complete — starting dev servers (Quarkus applies migrations at startup)"
+exec "$SCRIPT_DIR/dev.sh"