docs: add Skills plugin installation to MCP and Skills tab

The tab previously only covered MCP server setup. Add the
Claude Code plugin installation path (which installs both
skills and MCP server) as the recommended option, and move
MCP-only setup into a subsection for other editors.

Addresses feedback from James on #450.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: djsauble

docs/install-flox/ide-extensions.md

@@ -67,29 +67,33 @@ description: IDE extensions and AI agent integrations for Flox
 
 === "MCP and Skills"
 
-    [Flox Agentic][agentic] is an MCP server and skill library that
-    gives AI coding agents access to Flox environments.
+    [Flox Agentic][agentic] is a skill library and MCP server
+    that gives AI coding agents access to Flox environments.
 
     ## Install the MCP server
 
+    Every editor needs the Flox MCP server package:
+
     ```{ .sh .code-command .copy }
     flox install flox/flox-mcp-server
     ```
 
-    ## Claude Code
+    ## Claude Code (recommended)
 
-    Add the MCP server to your project:
+    The Flox Agentic plugin for Claude Code adds seven expert
+    skills and configures the MCP connection automatically:
 
     ```{ .sh .code-command .copy }
-    claude mcp add flox -- flox-mcp
+    /plugin marketplace add flox/flox-agentic
     ```
 
-    Or add it user-wide:
-
     ```{ .sh .code-command .copy }
-    claude mcp add --scope user flox -- flox-mcp
+    /plugin install flox@flox-agentic
     ```
 
+    The skills cover environments, services, builds,
+    containers, publishing, sharing, and CUDA development.
+
     ## Cursor
 
     Add the following to `~/.cursor/mcp.json`:
@@ -106,8 +110,6 @@ description: IDE extensions and AI agent integrations for Flox
 
     ## Other MCP clients
 
-    Any editor or agent that supports the
-    [Model Context Protocol][mcp] can use Flox Agentic.
     Point your client at the `flox-mcp` command using stdio
     transport.