fix(node-agent): mount SSH key to /home/homelab/.ssh on piha/solaria/chelsty-infra

Container runs as uid 1000 (homelab), HOME=/home/homelab. ssh without -i
looks for $HOME/.ssh — mounting to /root/.ssh was never visible to the
process user and caused silent Permission denied on event shipping.

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

hosts/chelsty-infra/runtime/node-agent/docker-compose.override.yml

@@ -8,4 +8,4 @@ services:
       - VPS_EVENTS_PATH=/opt/homelab/events
       - CHECK_INTERVAL=60
     volumes:
-      - /home/oskar/.ssh:/root/.ssh:ro
+      - /home/oskar/.ssh:/home/homelab/.ssh:ro

hosts/piha/runtime/node-agent/docker-compose.override.yml

@@ -8,4 +8,4 @@ services:
       - VPS_EVENTS_PATH=/opt/homelab/events
       - CHECK_INTERVAL=60
     volumes:
-      - /home/oskar/.ssh:/root/.ssh:ro
+      - /home/oskar/.ssh:/home/homelab/.ssh:ro

hosts/solaria/runtime/node-agent/docker-compose.override.yml

@@ -8,4 +8,4 @@ services:
       - VPS_EVENTS_PATH=/opt/homelab/events
       - CHECK_INTERVAL=60
     volumes:
-      - /home/oskar/.ssh:/root/.ssh:ro
+      - /home/oskar/.ssh:/home/homelab/.ssh:ro