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/deploy-bluegreen.sh

@@ -59,24 +59,27 @@ docker build -f infra/Dockerfile.registry -t apix-registry:latest . -q
 docker build -f infra/Dockerfile.portal   -t apix-portal:latest   . -q
 docker build -f infra/Dockerfile.demo     -t apix-demo:latest     . -q
 docker build -f infra/Dockerfile.spider   -t apix-spider:latest   . -q
+docker build -f infra/Dockerfile.admin    -t apix-admin:latest    . -q
 
 # ── 4. Rolling restart: a-stack (registry-a → portal-a + demo-a) ─────────────
 log "Rolling restart: a-stack..."
 $COMPOSE up -d --no-deps --force-recreate registry-a
 wait_healthy "registry-a"
 
-$COMPOSE up -d --no-deps --force-recreate portal-a demo-a
+$COMPOSE up -d --no-deps --force-recreate portal-a demo-a admin-a
 wait_healthy "portal-a"
 wait_healthy "demo-a"
+wait_healthy "admin-a"
 
 # ── 5. Rolling restart: b-stack ───────────────────────────────────────────────
 log "Rolling restart: b-stack..."
 $COMPOSE up -d --no-deps --force-recreate registry-b
 wait_healthy "registry-b"
 
-$COMPOSE up -d --no-deps --force-recreate portal-b demo-b
+$COMPOSE up -d --no-deps --force-recreate portal-b demo-b admin-b
 wait_healthy "portal-b"
 wait_healthy "demo-b"
+wait_healthy "admin-b"
 
 # ── 6. Spider (cron job — restart acceptable) ─────────────────────────────────
 log "Restarting spider..."