docs: add Related sections to 10 concept pages

Add cross-linking Related sections to concept pages that were dead ends:
- model-providers, models, context, context-engine, agent-workspace,
  architecture, messages, streaming, compaction, oauth

Each page now links to 3-4 related topics for navigation continuity.

docs/concepts/agent-workspace.md

@@ -234,3 +234,10 @@ Suggested `.gitignore` starter:
   [Channel routing](/channels/channel-routing) for routing configuration.
 - If `agents.defaults.sandbox` is enabled, non-main sessions can use per-session sandbox
   workspaces under `agents.defaults.sandbox.workspaceRoot`.
+
+## Related
+
+- [Standing Orders](/automation/standing-orders) — persistent instructions in workspace files
+- [Heartbeat](/gateway/heartbeat) — HEARTBEAT.md workspace file
+- [Session](/concepts/session) — session storage paths
+- [Sandboxing](/gateway/sandboxing) — workspace access in sandboxed environments

docs/concepts/architecture.md

@@ -135,3 +135,10 @@ Details: [Gateway protocol](/gateway/protocol), [Pairing](/channels/pairing),
 - Exactly one Gateway controls a single Baileys session per host.
 - Handshake is mandatory; any non‑JSON or non‑connect first frame is a hard close.
 - Events are not replayed; clients must refresh on gaps.
+
+## Related
+
+- [Agent Loop](/concepts/agent-loop) — detailed agent execution cycle
+- [Gateway Protocol](/gateway/protocol) — WebSocket protocol contract
+- [Queue](/concepts/queue) — command queue and concurrency
+- [Security](/gateway/security) — trust model and hardening

docs/concepts/compaction.md

@@ -84,3 +84,10 @@ survive.
 For advanced configuration (reserve tokens, identifier preservation, custom
 context engines, OpenAI server-side compaction), see the
 [Session Management Deep Dive](/reference/session-management-compaction).
+
+## Related
+
+- [Session](/concepts/session) — session management and lifecycle
+- [Session Pruning](/concepts/session-pruning) — trimming tool results
+- [Context](/concepts/context) — how context is built for agent turns
+- [Hooks](/automation/hooks) — compaction lifecycle hooks (before_compaction, after_compaction)

docs/concepts/context-engine.md

@@ -266,3 +266,9 @@ OpenClaw resolves when it needs a context engine.
 
 See also: [Compaction](/concepts/compaction), [Context](/concepts/context),
 [Plugins](/tools/plugin), [Plugin manifest](/plugins/manifest).
+
+## Related
+
+- [Context](/concepts/context) — how context is built for agent turns
+- [Plugin Architecture](/plugins/architecture) — registering context engine plugins
+- [Compaction](/concepts/compaction) — summarizing long conversations

docs/concepts/context.md

@@ -170,3 +170,10 @@ pluggable interface, lifecycle hooks, and configuration.
 - `System prompt (estimate)` = computed on the fly when no run report exists (or when running via a CLI backend that doesn’t generate the report).
 
 Either way, it reports sizes and top contributors; it does **not** dump the full system prompt or tool schemas.
+
+## Related
+
+- [Context Engine](/concepts/context-engine) — custom context injection via plugins
+- [Compaction](/concepts/compaction) — summarizing long conversations
+- [System Prompt](/concepts/system-prompt) — how the system prompt is built
+- [Agent Loop](/concepts/agent-loop) — the full agent execution cycle

docs/concepts/messages.md

@@ -152,3 +152,10 @@ Outbound message formatting is centralized in `messages`:
 - Reply threading via `replyToMode` and per-channel defaults
 
 Details: [Configuration](/gateway/configuration-reference#messages) and channel docs.
+
+## Related
+
+- [Streaming](/concepts/streaming) — real-time message delivery
+- [Retry](/concepts/retry) — message delivery retry behavior
+- [Queue](/concepts/queue) — message processing queue
+- [Channels](/channels) — messaging platform integrations

docs/concepts/model-providers.md

@@ -590,3 +590,10 @@ openclaw models list
 ```
 
 See also: [/gateway/configuration](/gateway/configuration) for full configuration examples.
+
+## Related
+
+- [Models](/concepts/models) — model configuration and aliases
+- [Model Failover](/concepts/model-failover) — fallback chains and retry behavior
+- [Configuration Reference](/gateway/configuration-reference#agent-defaults) — model config keys
+- [Providers](/providers) — per-provider setup guides

docs/concepts/models.md

@@ -223,3 +223,10 @@ Merge mode precedence for matching provider IDs:
 
 Marker persistence is source-authoritative: OpenClaw writes markers from the active source config snapshot (pre-resolution), not from resolved runtime secret values.
 This applies whenever OpenClaw regenerates `models.json`, including command-driven paths like `openclaw agent`.
+
+## Related
+
+- [Model Providers](/concepts/model-providers) — provider routing and auth
+- [Model Failover](/concepts/model-failover) — fallback chains
+- [Image Generation](/tools/image-generation) — image model configuration
+- [Configuration Reference](/gateway/configuration-reference#agent-defaults) — model config keys

docs/concepts/oauth.md

@@ -185,3 +185,9 @@ Related docs:
 
 - [/concepts/model-failover](/concepts/model-failover) (rotation + cooldown rules)
 - [/tools/slash-commands](/tools/slash-commands) (command surface)
+
+## Related
+
+- [Authentication](/gateway/authentication) — model provider auth overview
+- [Secrets](/gateway/secrets) — credential storage and SecretRef
+- [Configuration Reference](/gateway/configuration-reference#auth-storage) — auth config keys

docs/concepts/streaming.md

@@ -153,3 +153,9 @@ Slack:
 - `partial` can use Slack native streaming (`chat.startStream`/`append`/`stop`) when available.
 - `block` uses append-style draft previews.
 - `progress` uses status preview text, then final answer.
+
+## Related
+
+- [Messages](/concepts/messages) — message lifecycle and delivery
+- [Retry](/concepts/retry) — retry behavior on delivery failure
+- [Channels](/channels) — per-channel streaming support