docs: update custom chart type docs for the gallery sidebar

data-apps/external-connections.mdx

@@ -9,7 +9,7 @@ A data app can also fetch from third-party HTTP APIs — for example, your own p
 
 External connections are managed under **Project Settings → Data app connections** on the project.
 
-[Project chart types](/explore/chart-types/custom-project-charts#linking-external-connections) link connections the same way, so a chart type can call an API or show images from a URL field.
+[Custom chart types](/explore/chart-types/custom-project-charts#linking-external-connections) link connections the same way, so a chart type can call an API or show images from a URL field.
 
 ## Configuring a connection
 

explore/chart-types.mdx

@@ -6,10 +6,19 @@ doc-type: reference
 
 In Lightdash, the data in your results tables can be visualized in a bunch of different ways.
 
-**Custom** is one entry in the chart type menu covering two kinds of chart. A [Vega chart](/explore/chart-types/custom-vega-charts) is a one-off spec written in a JSON editor and belongs to that chart alone. A [project chart type](/explore/chart-types/custom-project-charts) is reusable: you describe the chart you want, Lightdash builds it, and anyone in the project can then apply it like a built-in chart type.
+**Custom** is one entry in the chart type menu covering two kinds of chart. A [Vega chart](/explore/chart-types/custom-vega-charts) is a one-off spec written in a JSON editor and belongs to that chart alone. A [custom chart type](/explore/chart-types/custom-project-charts) is reusable: you describe the chart you want, Lightdash builds it, and anyone in the project can then apply it like a built-in chart type.
 
-The visualization type that you pick determines how Lightdash shows the data series in your chart. To change how your data is displayed, click **Configure** when you're querying from a table. You have the option to change the chart type in the drop-down:
+The visualization type that you pick determines how Lightdash shows the data series in your chart. To change how your data is displayed, click **Configure** when you're querying from a table. The **Configure chart** sidebar opens on the right. Click **Change** next to the current chart type to open the chart type gallery, then pick a card:
 
 <Frame>
-  ![The chart type drop-down open in the Configure panel, listing bar, line, area, scatter, pie and the other chart types](/images/explore/chart-types/select-chart-type.png)
+  <img
+    alt="The Configure chart sidebar in the Explorer with the chart type gallery open, listing custom chart types above the built-in ones"
+    className="block dark:hidden"
+    src="/images/explore/chart-types/select-chart-type-light.png"
+  />
+  <img
+    alt="The Configure chart sidebar in the Explorer with the chart type gallery open, listing custom chart types above the built-in ones"
+    className="hidden dark:block"
+    src="/images/explore/chart-types/select-chart-type-dark.png"
+  />
 </Frame>

explore/chart-types/custom-project-charts.mdx

@@ -1,21 +1,21 @@
 ---
-title: "Custom project charts"
+title: "Custom chart types"
 sidebarTitle: "Custom"
 description: "Reusable chart types you build once for your project, then use like any built-in chart type"
 doc-type: reference
 icon: "shape"
 ---
 
-Project chart types are reusable chart types you build for your project. You describe the chart you want, Lightdash builds it, and anyone in the project can then use it like a built-in chart type. Open **Configure** in the Explorer, click **Change**, and pick it from the **Project** group of the chart type picker.
+Custom chart types are reusable chart types you build for your project. You describe the chart you want, Lightdash builds it, and anyone in the project can then use it like a built-in chart type. Open **Configure** in the Explorer, click **Change**, and pick it from the **Custom** group of the chart type gallery.
 
 For a one-off chart written directly as a Vega-Lite spec, see [Custom Vega charts](/explore/chart-types/custom-vega-charts).
 
-A project chart type is a chart type you build once and reuse. Describe the chart you want - a calendar heatmap, a hexbin map, a custom KPI layout - and Lightdash builds it, along with the inputs it needs (for example a "Category" dimension and a "Value" metric). Anyone in the project can then pick it as a chart type, map their own fields to its inputs, and save the result like any other chart.
+A custom chart type is a chart type you build once and reuse. Describe the chart you want - a calendar heatmap, a hexbin map, a custom KPI layout - and Lightdash builds it, along with the inputs it needs (for example a "Category" dimension and a "Value" metric). Anyone in the project can then pick it as a chart type, map their own fields to its inputs, and save the result like any other chart.
 
 The same chart type can power many saved charts, each with its own query and field mapping.
 
 <Info>
-  Project chart types are an enterprise feature and require the [data apps runtime](/self-host/enterprise-features/data-apps) to be enabled.
+  Custom chart types are an enterprise feature and require the [data apps runtime](/self-host/enterprise-features/data-apps) to be enabled.
 </Info>
 
 ## Browsing chart types
@@ -41,24 +41,24 @@ Each card previews the chart type with sample data. Click a card to see its desc
 
 Click **New chart type** in the gallery to open the builder, then describe the chart you want.
 
-The builder previews the chart type with sample data as it's built. The **Configure** panel beside the preview holds the display options the chart type declares, along with a color palette to preview it against. Follow-up prompts create new versions, and **History** opens a panel where you can view an earlier version or restore it.
+The builder previews the chart type with sample data as it's built. The **Generated options** panel beside the preview holds the display options the chart type declares, along with a color palette to preview it against. Follow-up prompts create new versions, and **History** opens a panel where you can view an earlier version or restore it.
 
 Name and describe the chart type in the header - that's what people see in the gallery and in the chart type picker. When it looks right, click **Preview in explorer** to try it against a real query.
 
 <Frame>
   <img
-    alt="The chart type builder, with the sample-data preview, the Configure panel, and the prompt bar"
+    alt="The chart type builder, with the generated options panel, the sample-data preview, the version history, and the prompt bar"
     className="block dark:hidden"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-builder-light.png"
   />
   <img
-    alt="The chart type builder, with the sample-data preview, the Configure panel, and the prompt bar"
+    alt="The chart type builder, with the generated options panel, the sample-data preview, the version history, and the prompt bar"
     className="hidden dark:block"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-builder-dark.png"
   />
 </Frame>
 
-You can also start one from any chart, without leaving the Explorer: open **Configure**, click **Change**, and choose **Create new chart type** in the **Project** group. The builder opens in the chart panel and previews against your query's real results.
+You can also start one from any chart, without leaving the Explorer: open **Configure**, click **Change**, and pick the **New chart type** tile in the **Custom** group. The builder opens in the chart panel, the sidebar switches to its generated options, and the preview uses your query's real results. To edit a chart type you already have selected, click the pencil next to its name in the **Configure chart** sidebar.
 
 <Tip>
   Chart types can also be developed on your machine and uploaded with the CLI. See [Chart types as code](#chart-types-as-code).
@@ -123,21 +123,21 @@ Once linked, the connection stays with the chart type across versions and everyw
     Select the dimensions and metrics your chart needs and run the query. You have to run it before you can pick a custom chart type.
   </Step>
   <Step title="Pick the chart type">
-    Open **Configure**, click **Change**, then pick one from the **Project** group in the chart type picker. Only chart types that finished building are listed.
+    Open **Configure** to open the chart sidebar, then click **Change**. The **Custom** group at the top of the gallery lists the project's chart types; click the **more** tile to see the rest, or search the gallery by name. Only chart types that finished building are listed.
   </Step>
   <Step title="Map your fields">
-    Each of the chart type's inputs gets a field picker, the same as configuring axes on a bar or line chart. Required inputs can't be cleared.
+    Each of the chart type's inputs gets a field picker in the **General** tab, the same as configuring axes on a bar or line chart. Required inputs can't be cleared. The chart type's own display options sit in the tabs beside it.
   </Step>
 </Steps>
 
 <Frame>
   <img
-    alt="The Custom chart type picker open in the Explorer, listing the built-in Vega editor and the project's own chart types"
+    alt="The Choose chart type panel in the Explorer sidebar, with the project's custom chart types listed above the built-in ones"
     className="block dark:hidden"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-picker-light.png"
   />
   <img
-    alt="The Custom chart type picker open in the Explorer, listing the built-in Vega editor and the project's own chart types"
+    alt="The Choose chart type panel in the Explorer sidebar, with the project's custom chart types listed above the built-in ones"
     className="hidden dark:block"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-picker-dark.png"
   />
@@ -147,23 +147,46 @@ The chart re-renders as you change the mapping or the underlying query.
 
 <Frame>
   <img
-    alt="A project chart type selected in the Explorer, with its inputs mapped to the query's fields and the chart rendering"
+    alt="A custom chart type selected in the Explorer sidebar, with its inputs mapped to the query's fields and the chart rendering"
     className="block dark:hidden"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-mapping-light.png"
   />
   <img
-    alt="A project chart type selected in the Explorer, with its inputs mapped to the query's fields and the chart rendering"
+    alt="A custom chart type selected in the Explorer sidebar, with its inputs mapped to the query's fields and the chart rendering"
     className="hidden dark:block"
     src="/images/explore/chart-types/custom-project-charts/custom-chart-types-mapping-dark.png"
   />
 </Frame>
 
 ## Saving and dashboards
 
-Save the chart like any other chart. The saved chart remembers which chart type it uses and how its inputs are mapped.
+Save the chart like any other chart. The saved chart remembers which chart type it uses, how its inputs are mapped, and which version of the chart type it uses (see [Versions and upgrades](#versions-and-upgrades)).
 
 Saved charts render in chart view and as dashboard tiles, driven by each surface's own query - dashboard filters and [date zoom](/explore/dashboards/date-zoom) apply like any other chart tile.
 
+## Versions and upgrades
+
+Every follow-up prompt in the builder creates a new version of the chart type. A saved chart keeps using the version it was saved with, so changing a chart type never changes the charts that already use it.
+
+When you edit a chart and a newer version of its chart type exists, the **Configure chart** sidebar shows **Newer version available**. Click **Review upgrade** to see what changed: inputs and options that were added, renamed or removed, and any change to the color palette.
+
+<Frame>
+  <img
+    alt="The Upgrade chart type dialog over the Explorer, listing what changed since the chart's version"
+    className="block dark:hidden"
+    src="/images/explore/chart-types/custom-project-charts/custom-chart-types-upgrade-light.png"
+  />
+  <img
+    alt="The Upgrade chart type dialog over the Explorer, listing what changed since the chart's version"
+    className="hidden dark:block"
+    src="/images/explore/chart-types/custom-project-charts/custom-chart-types-upgrade-dark.png"
+  />
+</Frame>
+
+Click **Upgrade** to move the chart to the latest version. Only that chart moves, and nothing changes until you save it. If the new version added a required input, map a field to it and the chart renders again.
+
+The builder has its own upgrade, for the chart type itself. When a chart type was built on an older version of the data apps runtime, the builder header shows **Upgrade available**. Starting it rebuilds the chart type as a new version, and **History** shows what's new. How the chart type renders doesn't change unless you ask for it in a follow-up prompt.
+
 ## Chart types as code
 
 Chart types round-trip through the CLI as their own resource, separate from data apps. Each one downloads to `lightdash/chart-types/<slug>/` as a locally buildable project you can version in git, edit, validate with [`lightdash apps validate`](/workflow/cli/reference#lightdash-apps-validate), and upload back: