feat: schedules UI, task cron type, monthly/yearly schedules, AE DB tools, integrations page

- Schedules web UI (/settings/crons): list, add, edit, pause/resume, delete jobs
- cron task type: full orchestrator tool loop on a schedule, result → notification channel
- parse_schedule: monthly/yearly formats (monthly:DD:HH:MM, yearly:MM:DD:HH:MM)
- HA inbound webhook tools toggle: orchestrator loop vs. direct LLM, configurable in UI
- ae_db_query/describe/show_view: SELECT-only Aether MariaDB access (admin, per-user creds)
- /settings/integrations: admin-only page for Aether DB credentials
- Schedules nav link added to all settings pages
- pymysql added to requirements
- Docs updated: HELP.md, MASTER.md, CLAUDE.md

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

cortex/static/help.html

@@ -94,6 +94,8 @@
     <a href="/settings" class="nav-link" id="nav-settings">Settings</a>
     <a href="/settings/notifications" class="nav-link">Notifications</a>
     <a href="/settings/tools" class="nav-link">Tools</a>
+    <a href="/settings/crons" class="nav-link">Schedules</a>
+    {{ integrations_nav }}
     <span class="nav-spacer"></span>
     <a href="/logout" class="nav-link nav-logout">Sign out</a>
   </nav>