feat: catch-all page for stopped apps, deploy controls, dashboard open button

Stopped/undeployed app subdomains now show a branded page instead of
Traefik 404. Deploy settings page gains start/stop/restart controls.
Dashboard shows "Megnyitás" button for running apps.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/docker-compose.yml

@@ -53,6 +53,13 @@ services:
       - "traefik.http.routers.controller.tls=true"
       - "traefik.http.services.controller.loadbalancer.server.port=8080"
       - "traefik.docker.network=traefik-public"
+      # Catch-all: branded error page for stopped/undeployed app subdomains
+      - "traefik.http.routers.catchall.rule=HostRegexp(`.+`)"
+      - "traefik.http.routers.catchall.priority=1"
+      - "traefik.http.routers.catchall.entrypoints=websecure"
+      - "traefik.http.routers.catchall.tls=true"
+      - "traefik.http.routers.catchall.tls.certresolver=letsencrypt"
+      - "traefik.http.routers.catchall.service=controller"
       # Health check labels for monitoring
       - "felhom.managed=true"
       - "felhom.component=controller"