docs(server): add detailed server configuration documentation

Author: yarlson

www/docs/configuration/index.md

@@ -51,7 +51,7 @@ FTL supports environment variable substitution in your configuration:
 Each section of the configuration has its own detailed documentation:
 
 - [Project Settings](./project-settings.md) - Core project configuration
-- [Server Configuration](./services.md) - Server and SSH settings
+- [Server Configuration](./server.md) - Server and SSH settings
 - [Services](./services.md) - Application service definitions
 - [Dependencies](./dependencies.md) - Supporting service configuration
 - [Volumes](./volumes.md) - Persistent storage management

www/docs/configuration/server.md

@@ -0,0 +1,81 @@
+---
+title: Server Configuration
+description: Configure deployment server settings in your FTL configuration
+---
+
+# Server Configuration
+
+The `server` section in your `ftl.yaml` defines the deployment target settings. All fields in this section are optional and come with smart defaults.
+
+## Configuration Fields
+
+```yaml
+server:
+  host: my-project.example.com
+  port: 22
+  user: deployer
+  ssh_key: ~/.ssh/id_rsa
+```
+
+| Field     | Description                                                | Default Value |
+| --------- | ---------------------------------------------------------- | ------------- |
+| `host`    | Hostname or IP address of the deployment server           | Value from `project.domain` |
+| `port`    | SSH port for connecting to the server                     | `22` |
+| `user`    | SSH user for deployment                                   | Current system user |
+| `ssh_key` | Path to SSH private key                                   | Auto-detected from standard locations |
+
+## Smart Defaults
+
+FTL implements intelligent defaults to minimize configuration:
+
+1. `host` defaults to your project's domain
+2. `user` defaults to your current system username
+3. `ssh_key` is auto-detected from standard SSH key locations
+4. `port` defaults to the standard SSH port 22
+
+## Environment Variables
+
+Server settings support environment variable substitution:
+
+```yaml
+server:
+  host: ${SERVER_HOST}
+  user: ${SERVER_USER}
+  ssh_key: ${SSH_KEY_PATH}
+```
+
+All environment variables must be set in the environment before running FTL commands.
+
+## Examples
+
+### Minimal Configuration
+
+When you're happy with the defaults, you can omit the entire `server` section:
+
+```yaml
+project:
+  name: my-project
+  domain: my-project.example.com
+  email: my-project@example.com
+```
+
+### Custom Server Settings
+
+When you need to customize server settings:
+
+```yaml
+server:
+  host: 192.168.1.100
+  user: custom-user
+  ssh_key: ~/.ssh/custom-key
+```
+
+### Mixed Defaults and Custom Settings
+
+You can specify only the fields you want to customize:
+
+```yaml
+server:
+  host: custom-host.example.com
+  user: deployer
+```