chore: add env_file: stack.env to all compose services

Portainer git-stack deployments require an explicit env_file reference
in the compose file to load variables from the repo's stack.env.
Adds env_file: [stack.env] before every service-level environment:
block across all 10 stacks.

stacks/notify/docker-compose.yml

@@ -13,6 +13,8 @@ services:
       - serve
     restart: unless-stopped
     networks: [edge]
+    env_file:
+      - stack.env
     environment:
       - TZ=${TZ}
       - NTFY_DEFAULT_HOST=https://ntfy.ginnoir.com
@@ -55,6 +57,8 @@ services:
       - /config/freshrss/extensions:/var/www/FreshRSS/extensions
     ports:
       - "9999:80"
+    env_file:
+      - stack.env
     environment:
       - CRON_MIN=3,33
       - TRUSTED_PROXY=172.16.0.1/12 192.168.0.1/16
@@ -66,6 +70,8 @@ services:
     image: ghcr.io/verifiedjoseph/vigilant:latest
     restart: unless-stopped
     networks: [edge]
+    env_file:
+      - stack.env
     environment:
       - VIGILANT_NOTIFICATION_SERVICE=ntfy
       - VIGILANT_NOTIFICATION_NTFY_URL=https://ntfy.ginnoir.com/