Fix architecture pages to appear in sidebar TOC hierarchy

Create how-it-works/index.rst as a parent container with toctree
so that Architecture and Open Source vs SaaS pages appear nested
under "Overview" in the sidebar, matching the pattern used by
GitOps > ArgoCD. Previously they were listed flat as orphan pages.

https://claude.ai/code/session_0184fwhrjC4ELrYQBMCbyhfS

Author: claude

docs/conf.py

@@ -109,7 +109,7 @@
     "tutorials/routing-silencing.html": "/master/notification-routing/routing-silencing.html",
     "configuration/configuring-sinks.html": "/master/notification-routing/configuring-sinks.html",
     "how-it-works/privacy-and-security.html": "/master/setup-robusta/privacy-and-security.html",
-    "how-it-works/index.html": "/master/playbook-reference/what-are-playbooks.html",
+    # "how-it-works/index.html": "/master/playbook-reference/what-are-playbooks.html",  # removed: now a real page
     "playbook-reference/examples.html": "/master/playbook-reference/builtin-alert-enrichment.html",
     "playbook-reference/prometheus-examples/index.html": "/master/playbook-reference/builtin-alert-enrichment.html",
     "tutorials/playbook-track-changes.html": "/master/playbook-reference/kubernetes-examples/kubernetes-change-notifications.html",

docs/how-it-works/index.rst

@@ -0,0 +1,28 @@
+:hide-toc:
+
+Overview
+====================
+
+.. grid:: 1 1 2 3
+    :gutter: 2
+
+    .. grid-item-card:: :octicon:`cpu;1em;` Architecture
+        :class-card: sd-bg-text-light
+        :link: architecture
+        :link-type: doc
+
+        How Robusta's components work together — the Agent, HolmesGPT, data sources, and the Platform.
+
+    .. grid-item-card:: :octicon:`package;1em;` Open Source vs SaaS
+        :class-card: sd-bg-light sd-bg-text-light
+        :link: oss-vs-saas
+        :link-type: doc
+
+        Compare deployment options: open source HolmesGPT, SaaS, and self-hosted.
+
+.. toctree::
+   :maxdepth: 1
+   :hidden:
+
+   Architecture <architecture>
+   Open Source vs SaaS <oss-vs-saas>

docs/index.rst

@@ -1,13 +1,12 @@
 :hide-toc:
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 4
    :caption: Overview
    :hidden:
 
    self
-   how-it-works/architecture
-   how-it-works/oss-vs-saas
+   how-it-works/index
 
 .. toctree::
    :maxdepth: 4