fix(addon): bot presence — fix network isolation, computed field write, and timer gap

- docker-compose.odoo.yml: add activeblue-net so Odoo can reach
  activeblue-agent by hostname; fix addons volume mount (was odoo_module)
- ab_ai_bot.py: bus.presence.status is computed — write only last_poll
  and last_presence; set last_poll 90s ahead when online so the bot
  stays green across the 60s cron cycle (DISCONNECTION_TIMER=30s)
- ir_cron.xml: reduce ping interval to 20s (uses Odoo 18 seconds type)

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

docker-compose.odoo.yml

@@ -13,7 +13,7 @@ services:
     volumes:
       - ./odoo-ai-data:/var/lib/odoo
       - ./odoo-ai-config:/etc/odoo
-      - ./odoo_module:/mnt/extra-addons
+      - ./addons:/mnt/extra-addons
     ports: []
     restart: unless-stopped
     labels:
@@ -25,6 +25,7 @@ services:
     networks:
       - traefik-public
       - odoo-ai-internal
+      - activeblue-net
 
   odoo-ai-db:
     image: postgres:15
@@ -48,6 +49,8 @@ networks:
     external: true
   odoo-ai-internal:
     driver: bridge
+  activeblue-net:
+    external: true
 
 volumes:
   odoo-ai-db-data: