Remove registry groups from documentation (#938)

Registry groups are deprecated and no longer surfaced by the CLI or UI
with the upstream registry format. Remove the registry-groups sections
from the CLI and UI registry guides and drop groups references from the
registry schema reference.

The runtime-groups content nested under the CLI registry-groups section
is already covered by the group management guide and run-mcp-servers, so
remove it here and point to group management from Next steps instead.

Closes #815.

Co-authored-by: Dan Barr <6922515+danbarr@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: danbarr

docs/toolhive/guides-cli/registry.mdx

@@ -234,91 +234,14 @@ thv config unset-registry
 
 This restores the default behavior of using ToolHive's built-in registry.
 
-## Organize servers with registry groups
-
-Registry groups allow you to organize related MCP servers and run them together
-as a cohesive unit. This is particularly useful for creating team-specific
-toolkits, workflow-based server collections, or environment-specific
-configurations.
-
-:::note
-
-Registry groups are different from [runtime groups](./group-management.mdx).
-Registry groups organize server definitions within registry files, while runtime
-groups organize running server instances for access control.
-
-:::
-
-### Group structure
-
-Groups are defined under `data.groups` in your custom registry. Each group has a
-name, description, and an array of servers:
-
-```json
-{
-  "data": {
-    "servers": [
-      // Individual servers
-    ],
-    "groups": [
-      {
-        "name": "group-name",
-        "description": "Description of what this group provides",
-        "servers": [
-          // Complete server definitions
-        ]
-      }
-    ]
-  }
-}
-```
-
-See the [registry schema](../reference/registry-schema-upstream.mdx) for the
-full server object structure.
-
-### Key characteristics
-
-- **Optional**: Groups are entirely optional. Omit the `groups` section if you
-  only need individual servers
-- **Independent server definitions**: Each group contains complete server
-  configurations, not references to top-level servers
-- **Self-contained**: Groups can define servers with the same names as top-level
-  servers but with different configurations
-- **Flexible membership**: The same server can appear in multiple groups with
-  different configurations
-
-### Full example
-
-For a complete custom registry file with both top-level servers and groups, see
-the [Full example](../reference/registry-schema-upstream.mdx#full-example) in
-the registry schema reference.
-
-### Use registry servers with groups
-
-You can organize registry servers into runtime groups after running them:
-
-```bash
-thv group create dev-toolkit
-thv run --group dev-toolkit github
-thv run --group dev-toolkit heroku
-```
-
-You can pass environment variables and secrets to each server individually:
-
-```bash
-thv run --group dev-toolkit --secret github-token,target=GITHUB_PERSONAL_ACCESS_TOKEN github
-thv run --group dev-toolkit --secret heroku-key,target=HEROKU_API_KEY heroku
-```
-
-Groups provide a convenient way to start multiple related servers with a single
-command. See [Group management](./group-management.mdx) for more details on
-creating and managing groups.
-
 ## Next steps
 
 See [Run MCP servers](./run-mcp-servers.mdx) to run an MCP server from the
 registry.
 
+Learn how to [organize servers into groups](./group-management.mdx) to manage
+related servers together.
+
 Learn how to [create a custom MCP registry](../tutorials/custom-registry.mdx).
 
 ## Related information

docs/toolhive/guides-ui/registry.mdx

@@ -54,49 +54,6 @@ Click on any server in the registry to view detailed information including:
 This detailed view helps you understand the server's purpose and capabilities
 before adding it to your ToolHive installation.
 
-## Registry groups
-
-Registry groups allow you to organize related MCP servers and run them together
-as a cohesive unit. This is particularly useful for creating team-specific
-toolkits, workflow-based server collections, or environment-specific
-configurations.
-
-The default ToolHive registry contains only individual servers. To use groups,
-configure a [custom registry](../tutorials/custom-registry.mdx) that defines
-them.
-
-### Key characteristics
-
-- **Optional**: Groups are entirely optional. You only need a custom registry
-  with groups if you want to install multiple servers together
-- **Independent server definitions**: Each group contains complete server
-  configurations, not references to top-level servers
-- **Self-contained**: Groups can define servers with the same names as
-  individual servers but with different configurations
-- **Flexible membership**: The same server can appear in multiple groups with
-  different configurations
-
-### Browse and view groups
-
-When you use a custom registry that includes groups, they appear in the registry
-grid alongside individual servers. Click on any group to view its name,
-description, and a list of all included servers with their descriptions. From
-the group details page, you can click **Install group** to begin installation.
-
-### Install a group
-
-To install a group:
-
-1. Click **Install group** to open the wizard
-2. Configure each server following the same process as
-   [installing an individual server](./run-mcp-servers.mdx#configure-the-server)
-3. Click **Next** after each server, or **Finish** on the last one
-
-The wizard guides you through each server one at a time, showing your progress
-(for example, "Installing server 1 of 3"). After installation, the group appears
-in the **MCP Servers** page where you can
-[manage the servers together](./group-management.mdx).
-
 ## Registry settings
 
 To configure your registry, ToolHive provides a dedicated **Registry** settings

docs/toolhive/reference/registry-schema-upstream.mdx

@@ -2,8 +2,7 @@
 title: Registry JSON schema
 description:
   JSON schema reference for the ToolHive registry format, which builds on the
-  official MCP server schema and adds skills, groups, and publisher-provided
-  metadata.
+  official MCP server schema and adds skills and publisher-provided metadata.
 displayed_sidebar: toolhiveSidebar
 ---
 
@@ -14,15 +13,14 @@ import PublisherProvidedSchema from '@site/static/api-specs/publisher-provided.s
 import SkillSchema from '@site/static/api-specs/skill.schema.json';
 
 This is the ToolHive registry schema, built on the official MCP server schema
-with ToolHive-specific additions for skills, groups, and publisher-provided
-metadata. It defines the structure and constraints for registry entries,
-ensuring that all entries conform to a consistent format.
-
-The top-level `data` object holds three arrays: `servers` (objects conforming to
-the official MCP server schema), `skills` (objects conforming to the ToolHive
-skill schema, documented below), and `groups` (optional groupings). The schema
-requires `servers` to be present even when empty, so a skills-only file still
-needs `"servers": []`.
+with ToolHive-specific additions for skills and publisher-provided metadata. It
+defines the structure and constraints for registry entries, ensuring that all
+entries conform to a consistent format.
+
+The top-level `data` object holds two arrays: `servers` (objects conforming to
+the official MCP server schema) and `skills` (objects conforming to the ToolHive
+skill schema, documented below). The schema requires `servers` to be present
+even when empty, so a skills-only file still needs `"servers": []`.
 
 :::info