Rebalance swarm: promote all nodes to managers and remove hostname constraints

- Promoted p1, p2, p3 from worker to manager nodes for 4-node quorum
- Removed unnecessary hostname constraints from service configs
- Only traefik and portainer remain pinned to p0
- Services now auto-balance across all nodes via GlusterFS shared storage
- Updated README with cluster overview and distribution strategy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

stacks/apps/adminer/stack.yml

@@ -10,9 +10,6 @@ services:
     - ADMINER_DESIGN=nette
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
 networks:
   homelab:
     external: true

stacks/apps/authentik/stack.yml

@@ -10,9 +10,6 @@ services:
     - homelab
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
 
   authentik_server:
     image: ghcr.io/goauthentik/server:2025.10.0
@@ -38,9 +35,6 @@ services:
     - homelab
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
       labels:
         - "traefik.enable=true"
         - "traefik.http.routers.authentik.rule=Host(`auth.frostlabs.me`)"
@@ -75,9 +69,6 @@ services:
     - homelab
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
     depends_on:
     - redis
 

stacks/apps/n8n/stack.yml

@@ -17,9 +17,6 @@ services:
     - /var/run/docker.sock:/var/run/docker.sock:ro
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
       restart_policy:
         condition: on-failure
         delay: 5s

stacks/apps/paperless/stack.yml

@@ -5,9 +5,6 @@ services:
     - homelab
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
 
   paperless_webserver:
     image: ghcr.io/paperless-ngx/paperless-ngx:latest
@@ -48,9 +45,6 @@ services:
     - homelab
     deploy:
       replicas: 1
-      placement:
-        constraints:
-        - node.hostname == p0
     depends_on:                                      # Fixed: removed postgres dependency
     - paperless_redis
 

stacks/apps/uptime/stack.yml

@@ -14,9 +14,10 @@ services:
       retries: 3
       start_period: 60s
     deploy:
-      placement:
-        constraints: [node.hostname == p0]
       replicas: 1
+      placement:
+        preferences:
+        - spread: node.hostname
       restart_policy:
         condition: on-failure
         delay: 10s