docs: Batch 1 — create automation hub + add Related sections

New page: docs/automation/index.md — single entry point for all automation
mechanisms (heartbeat, cron, tasks, hooks, standing-orders, webhooks) with
a decision flowchart and comparison table.

Add "Related" sections to 5 high-traffic pages that were dead ends:
- gateway/heartbeat.md → links to tasks, cron-vs-heartbeat, timezone, troubleshooting
- concepts/session.md → links to multi-agent, tasks, channel-routing
- concepts/multi-agent.md → links to channel-routing, subagents, ACP, presence, session
- concepts/agent-loop.md → links to tools, hooks, compaction, exec-approvals, thinking
- concepts/timezone.md → links to heartbeat, cron-jobs, date-time

Add automation/index to Mintlify nav as first item in Automation group.

docs/automation/index.md

@@ -0,0 +1,73 @@
+---
+summary: "Overview of all automation mechanisms: heartbeat, cron, tasks, hooks, webhooks, and more"
+read_when:
+  - Deciding how to automate work with OpenClaw
+  - Choosing between heartbeat, cron, hooks, and webhooks
+  - Looking for the right automation entry point
+title: "Automation Overview"
+---
+
+# Automation
+
+OpenClaw provides several automation mechanisms, each suited to different use cases. This page helps you choose the right one.
+
+## Quick decision guide
+
+```
+Do you need something to run on a schedule?
+  YES → Is exact timing critical?
+    YES → Cron (isolated)
+    NO  → Can it batch with other checks?
+      YES → Heartbeat
+      NO  → Cron
+  NO → Continue...
+
+Do you need to react to an event (message, tool call, session change)?
+  YES → Hooks (or plugin hooks)
+
+Do you need to receive external HTTP events?
+  YES → Webhooks
+
+Do you want persistent instructions the agent always follows?
+  YES → Standing Orders
+
+Do you want to track what background work happened?
+  → Background Tasks (automatic for cron, ACP, subagents)
+```
+
+## Mechanisms at a glance
+
+| Mechanism | What it does | Runs in | Creates task record |
+|---|---|---|---|
+| [Heartbeat](/gateway/heartbeat) | Periodic main-session turn — batches multiple checks | Main session | No |
+| [Cron](/automation/cron-jobs) | Scheduled jobs with precise timing | Main or isolated session | Yes (all types) |
+| [Background Tasks](/automation/tasks) | Tracks detached work (cron, ACP, subagents, CLI) | N/A (ledger) | N/A |
+| [Hooks](/automation/hooks) | Event-driven scripts triggered by agent lifecycle events | Hook runner | No |
+| [Standing Orders](/automation/standing-orders) | Persistent instructions injected into the system prompt | Main session | No |
+| [Webhooks](/automation/webhook) | Receive inbound HTTP events and route to the agent | Gateway HTTP | No |
+
+### Specialized automation
+
+| Mechanism | What it does |
+|---|---|
+| [Gmail PubSub](/automation/gmail-pubsub) | Real-time Gmail notifications via Google PubSub |
+| [Polling](/automation/poll) | Periodic data source checks (RSS, APIs, etc.) |
+| [Auth Monitoring](/automation/auth-monitoring) | Credential health and expiry alerts |
+
+## How they work together
+
+The most effective setups combine multiple mechanisms:
+
+1. **Heartbeat** handles routine monitoring (inbox, calendar, notifications) in one batched turn every 30 minutes.
+2. **Cron** handles precise schedules (daily reports, weekly reviews) and one-shot reminders.
+3. **Hooks** react to specific events (tool calls, session resets, compaction) with custom scripts.
+4. **Standing Orders** give the agent persistent context ("always check the project board before replying").
+5. **Background Tasks** automatically track all detached work so you can inspect and audit it.
+
+See [Cron vs Heartbeat](/automation/cron-vs-heartbeat) for a detailed comparison of the two scheduling mechanisms.
+
+## Related
+
+- [Cron vs Heartbeat](/automation/cron-vs-heartbeat) — detailed comparison guide
+- [Troubleshooting](/automation/troubleshooting) — debugging automation issues
+- [Configuration Reference](/gateway/configuration-reference) — all config keys

docs/concepts/agent-loop.md

@@ -156,3 +156,11 @@ See [Plugin hooks](/plugins/architecture#provider-runtime-hooks) for the hook AP
 - AbortSignal (cancel)
 - Gateway disconnect or RPC timeout
 - `agent.wait` timeout (wait-only, does not stop agent)
+
+## Related
+
+- [Tools](/tools) — available agent tools
+- [Hooks](/automation/hooks) — event-driven scripts triggered by agent lifecycle events
+- [Compaction](/concepts/compaction) — how long conversations are summarized
+- [Exec Approvals](/tools/exec-approvals) — approval gates for shell commands
+- [Thinking](/tools/thinking) — thinking/reasoning level configuration

docs/concepts/multi-agent.md

@@ -550,3 +550,11 @@ If you need per-agent boundaries, use `agents.list[].tools` to deny `exec`.
 For group targeting, use `agents.list[].groupChat.mentionPatterns` so @mentions map cleanly to the intended agent.
 
 See [Multi-Agent Sandbox & Tools](/tools/multi-agent-sandbox-tools) for detailed examples.
+
+## Related
+
+- [Channel Routing](/channels/channel-routing) — how messages route to agents
+- [Sub-Agents](/tools/subagents) — spawning background agent runs
+- [ACP Agents](/tools/acp-agents) — running external coding harnesses
+- [Presence](/concepts/presence) — agent presence and availability
+- [Session](/concepts/session) — session isolation and routing

docs/concepts/session.md

@@ -111,3 +111,6 @@ Preview with `openclaw sessions cleanup --dry-run`.
 - [Session Tools](/concepts/session-tool) -- agent tools for cross-session work
 - [Session Management Deep Dive](/reference/session-management-compaction) --
   store schema, transcripts, send policy, origin metadata, and advanced config
+- [Multi-Agent](/concepts/multi-agent) — routing and session isolation across agents
+- [Background Tasks](/automation/tasks) — how detached work creates task records with session references
+- [Channel Routing](/channels/channel-routing) — how inbound messages are routed to sessions

docs/concepts/timezone.md

@@ -89,3 +89,9 @@ The system prompt includes:
 You can control the prompt format with `agents.defaults.timeFormat` (`auto` | `12` | `24`).
 
 See [Date & Time](/date-time) for the full behavior and examples.
+
+## Related
+
+- [Heartbeat](/gateway/heartbeat) — active hours use timezone for scheduling
+- [Cron Jobs](/automation/cron-jobs) — cron expressions use timezone for scheduling
+- [Date & Time](/date-time) — full date/time behavior and examples

docs/docs.json

@@ -1114,6 +1114,7 @@
               {
                 "group": "Automation",
                 "pages": [
+                  "automation/index",
                   "automation/hooks",
                   "automation/standing-orders",
                   "automation/cron-jobs",

docs/gateway/heartbeat.md

@@ -397,3 +397,11 @@ Heartbeats run full agent turns. Shorter intervals burn more tokens. To reduce c
 - Set a cheaper `model` (e.g. `ollama/llama3.2:1b`).
 - Keep `HEARTBEAT.md` small.
 - Use `target: "none"` if you only want internal state updates.
+
+## Related
+
+- [Automation Overview](/automation) — all automation mechanisms at a glance
+- [Cron vs Heartbeat](/automation/cron-vs-heartbeat) — when to use each
+- [Background Tasks](/automation/tasks) — how detached work is tracked
+- [Timezone](/concepts/timezone) — how timezone affects heartbeat scheduling
+- [Troubleshooting](/automation/troubleshooting) — debugging automation issues