feat(odoo): add activeblue_ai Odoo 18 module with OWL2 frontend

Models:
- ab.ai.bot: service URL, webhook secret, privacy mode, ping/dispatch
- ab.ai.directive: full directive lifecycle log with status tracking
- ab.ai.log: activity log with level/agent/record linkage
- ab.ai.agent.registry: agent list synced from agent service

Controllers:
- webhook.py: /ai/webhook/callback handles directive_completed, escalation, sweep_findings
- health_proxy.py: /ai/health proxies agent service detailed health
- approval.py: /ai/chat dispatch, /ai/approval/pending, /ai/approval/respond

Security:
- group_ai_user (chat) + group_ai_manager (configure, approve, logs)
- ir.model.access.csv for all 4 models

Views: list/form for bot, directives, logs, registry; main menu with AI brain icon

OWL2 frontend:
- systray_button.js: brain icon in top bar, status dot, pending approval badge
- ai_panel.js: slide-in chat panel, approval workflow, 30s poll for pending items
- CSS: slide-in animation, message bubbles, loading dots, approval section

Data: 4 cron jobs (ping, registry sync, directive/log cleanup)

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

addons/activeblue_ai/static/src/xml/systray.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<templates xml:space="preserve">
+    <t t-name="activeblue_ai.SystrayButton" owl="1">
+        <div class="o_menu_systray_item ab-ai-systray" t-on-click="togglePanel" t-att-title="statusTitle">
+            <i class="fa fa-brain ab-ai-brain-icon" t-att-class="iconClass"/>
+            <span t-if="state.pendingCount > 0" class="ab-ai-badge" t-esc="state.pendingCount"/>
+        </div>
+    </t>
+</templates>