Fix Caddy routing and add caddy_net to all Docker services

- lib/common.sh: fix broken reverse_proxy target — localhost inside Caddy's
  container is the container's own loopback, not the host; change to
  host.docker.internal so proxied ports are actually reachable
- services/caddy.sh: add extra_hosts host.docker.internal:host-gateway so
  the above resolves correctly; create caddy_net bridge network in Caddy's
  own compose so other services can reference it as external; update all
  Caddyfile template comments and README examples to match
- services/filebrowser.sh: update image tag from deprecated :s6 to :latest;
  remove non-functional PUID/PGID env vars (filebrowser/filebrowser does not
  honour them); add configure_caddy_for_service call; add caddy_net
- services/ntfy.sh: add configure_caddy_for_service call; add caddy_net
- services/portainer.sh: add configure_caddy_for_service call; add caddy_net
- services/frigate-notify.sh, watchtower.sh: add caddy_net for
  container-to-container comms (frigate, ntfy) without a Caddy call
- All remaining web-facing Docker services: add caddy_net network block to
  docker-compose and CADDY_NET to .env where applicable; services using
  network_mode: host (wolf-pair, lyrion) have the top-level block only

https://claude.ai/code/session_01UZus2Q9gNTfUdqSMrhuX29

services/homeassistant.sh

@@ -29,13 +29,16 @@ install_homeassistant() {
     echo "                 HomeKit, mDNS/Zeroconf, some Zigbee/Z-Wave & Bluetooth)."
     local HA_NETMODE=""
     prompt_text "  Choose networking mode [1]:" "1" HA_NETMODE
-    local HA_NET_LINES
+    local HA_NET_LINES HA_CADDY_NET_LINES
     if [ "$HA_NETMODE" = "2" ]; then
         HA_NET_LINES="    network_mode: host"
+        HA_CADDY_NET_LINES=""
         echo "  → Host networking selected (best device discovery)."
     else
         HA_NET_LINES="    ports:
       - \"8123:8123\""
+        HA_CADDY_NET_LINES="    networks:
+      - caddy_net"
         echo "  → Bridge networking selected (port 8123 published)."
     fi
 
@@ -55,6 +58,12 @@ services:
       - ./config:/config
       - /run/dbus:/run/dbus:ro
 ${HA_NET_LINES}
+${HA_CADDY_NET_LINES}
+
+networks:
+  caddy_net:
+    external: true
+    name: \${CADDY_NET:-caddy_net}
 HOMEASSISTANT_COMPOSE
 
     mkdir -p config