docs: add user guide with 9 MDX pages and screenshots

Adds comprehensive documentation covering McpMux concepts (Spaces,
FeatureSets, Clients, Gateway, Security), getting started guide,
server management, and server definition schema reference.

Content is sourced by mcpmux.discover.ui at build time via
fetch-docs.mjs and rendered with Fumadocs on mcpmux.com/docs.

Includes GitHub Action to trigger Cloudflare Pages rebuild when
docs change on main.

Signed-off-by: Mohammod Al Amin Ashik <maa.ashik00@gmail.com>

Author: its-mash

docs/guide/clients.mdx

@@ -23,7 +23,7 @@ McpMux works with any MCP-compatible client, including:
 
 All clients connect to the same endpoint: `http://localhost:45818/mcp`
 
-![Authorization Request dialog — VS Code connecting to McpMux with connection mode selection](/screenshots/clients.png)
+![Authorization Request dialog — VS Code connecting to McpMux with connection mode selection](https://mcpmux.com/screenshots/clients.png)
 
 ## Connection Modes
 
@@ -61,7 +61,7 @@ Each client receives **FeatureSet grants** per Space. This means a single client
 
 This is configured in the **Clients** page by selecting a client and managing its grants for each Space.
 
-![Client detail panel — Cursor with per-Space FeatureSet grants and permission management](/screenshots/client-detail.png)
+![Client detail panel — Cursor with per-Space FeatureSet grants and permission management](https://mcpmux.com/screenshots/client-detail.png)
 
 ## Access Keys
 
@@ -81,7 +81,7 @@ Clients can be registered in two ways:
 1. **Automatic** — when a new client connects to the gateway via OAuth, McpMux prompts you to approve it
 2. **Manual** — add a client through the McpMux UI and copy the access key into your client's configuration
 
-![Effective Features view showing 45 tools, 8 prompts, and 3 resources available to Cursor](/screenshots/client-permissions.png)
+![Effective Features view showing 45 tools, 8 prompts, and 3 resources available to Cursor](https://mcpmux.com/screenshots/client-permissions.png)
 
 ### Monitoring
 

docs/guide/feature-sets.mdx

@@ -15,7 +15,7 @@ Without permission control, every AI client connected through the gateway can ac
 
 FeatureSets solve this by letting you define exactly what each client can do.
 
-![FeatureSets page showing All Features, Default, Custom (Cloudflare Workers, Full Stack Dev, React Development, Read Only)](/screenshots/featuresets.png)
+![FeatureSets page showing All Features, Default, Custom (Cloudflare Workers, Full Stack Dev, React Development, Read Only)](https://mcpmux.com/screenshots/featuresets.png)
 
 ## FeatureSet Types
 
@@ -88,7 +88,7 @@ FeatureSets can **contain other FeatureSets**. This lets you build hierarchical
 
 ## Managing FeatureSets
 
-![React Development FeatureSet — configuring included features from each server](/screenshots/featureset-detail.png)
+![React Development FeatureSet — configuring included features from each server](https://mcpmux.com/screenshots/featureset-detail.png)
 
 ### Creating a Custom FeatureSet
 

docs/guide/gateway.mdx

@@ -70,7 +70,7 @@ The gateway maintains a pool of connections to backend MCP servers:
 
 This means if two clients in the same Space both use the GitHub server, they share a single connection to GitHub — reducing resource usage.
 
-![Dashboard showing gateway running on localhost:45818 with server stats and client configuration](/screenshots/dashboard.png)
+![Dashboard showing gateway running on localhost:45818 with server stats and client configuration](https://mcpmux.com/screenshots/dashboard.png)
 
 ## Starting and Stopping
 

docs/guide/getting-started.mdx

@@ -31,13 +31,13 @@ You can create additional Spaces later for different contexts:
 
 To create a Space, go to the **Spaces** page and click **Create Space**.
 
-![Space switcher in the sidebar lets you quickly switch between workspaces](/screenshots/space-switcher.png)
+![Space switcher in the sidebar lets you quickly switch between workspaces](https://mcpmux.com/screenshots/space-switcher.png)
 
 ## Step 3: Browse and Install a Server
 
 Navigate to **Discover Servers** in McpMux or browse the [server registry](/) on this website. You'll find 100+ MCP servers for popular tools.
 
-![Discover Servers page — browse, search, and install MCP servers from the registry](/screenshots/discover.png)
+![Discover Servers page — browse, search, and install MCP servers from the registry](https://mcpmux.com/screenshots/discover.png)
 
 Click **Install** on any server to add it to your active Space. Popular choices to start with:
 
@@ -60,7 +60,7 @@ See [Server Management](/docs/servers/) for details on all configuration options
 
 Go to the **Dashboard** and click **Start Gateway**. The gateway starts on `localhost:45818` and begins connecting to your enabled servers.
 
-![Dashboard with gateway running and connected servers](/screenshots/dashboard.png)
+![Dashboard with gateway running and connected servers](https://mcpmux.com/screenshots/dashboard.png)
 
 You'll see server status indicators change:
 - 🟡 **Connecting** — establishing MCP handshake

docs/guide/index.mdx

@@ -3,7 +3,7 @@ title: What is McpMux
 description: Configure MCP servers once, connect every AI client through a single endpoint. McpMux is a free desktop app and local gateway for MCP server management with encrypted credential storage.
 ---
 
-![McpMux desktop app — dashboard with gateway running, server stats, and client configuration](/screenshots/features-hero.png)
+![McpMux desktop app — dashboard with gateway running, server stats, and client configuration](https://mcpmux.com/screenshots/features-hero.png)
 
 ## The Problem
 
@@ -27,7 +27,7 @@ McpMux Gateway (localhost:45818/mcp)
 MCP Servers (GitHub, Slack, PostgreSQL, …)
 ```
 
-![McpMux dashboard showing gateway status, connected servers, FeatureSets, clients, and connection config](/screenshots/dashboard.png)
+![McpMux dashboard showing gateway status, connected servers, FeatureSets, clients, and connection config](https://mcpmux.com/screenshots/dashboard.png)
 
 McpMux sits between your AI clients and your MCP servers. It handles:
 

docs/guide/server-definitions.mdx

@@ -5,7 +5,7 @@ description: Learn how to create MCP server definitions for the McpMux registry.
 
 A **server definition** is a JSON file that describes an MCP server — how to run it, what credentials it needs, and what capabilities it provides. Server definitions power the [McpMux server registry](/) and enable one-click installation.
 
-![McpMux web registry — browse and install MCP servers with one click](/screenshots/discover-web.png)
+![McpMux web registry — browse and install MCP servers with one click](https://mcpmux.com/screenshots/discover-web.png)
 
 ## Required Fields
 

docs/guide/servers.mdx

@@ -22,7 +22,7 @@ You can also browse the registry inside the McpMux desktop app under **Discover
 
 For servers not in the registry, you can add them manually in McpMux by providing the server definition JSON directly.
 
-![My Servers page — installed servers with connection status, auth type, and transport badges](/screenshots/servers.png)
+![My Servers page — installed servers with connection status, auth type, and transport badges](https://mcpmux.com/screenshots/servers.png)
 
 ## Transport Types
 
@@ -98,7 +98,7 @@ Each installed server has an **enabled/disabled** toggle:
 
 Disabling a server immediately disconnects it and removes its tools from connected clients.
 
-![Expanded server view showing available tools and prompts for each connected server](/screenshots/server-expanded.png)
+![Expanded server view showing available tools and prompts for each connected server](https://mcpmux.com/screenshots/server-expanded.png)
 
 ## Connection Status
 

docs/guide/spaces.mdx

@@ -16,7 +16,7 @@ Without Spaces, all your MCP credentials and server configurations live in a sin
 
 Spaces solve this by providing **complete isolation** between environments.
 
-![Workspaces page showing My Space (active), Open Source, Personal, and Work spaces](/screenshots/spaces.png)
+![Workspaces page showing My Space (active), Open Source, Personal, and Work spaces](https://mcpmux.com/screenshots/spaces.png)
 
 ## How Spaces Work
 
@@ -37,7 +37,7 @@ Only one Space can be **active** at a time. The active Space determines:
 
 Switching the active Space immediately changes what servers and tools are available — no restart required.
 
-![Space switcher dropdown in the sidebar for quick context switching](/screenshots/space-switcher.png)
+![Space switcher dropdown in the sidebar for quick context switching](https://mcpmux.com/screenshots/space-switcher.png)
 
 ### Default-Enabled Servers