Add host server setup guide

Documents the host package covering:
- Basic server setup with code example
- Directory structure for WASM apps
- Static file serving and SPA fallback
- WASM MIME type configuration
- Automatic gzip compression
- Development vs production considerations

Closes #3

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

host/README.md

@@ -0,0 +1,120 @@
+# Host Package
+
+Static file server optimized for serving Iris WASM applications.
+
+## Basic Setup
+
+```go
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"git.flowmade.one/flowmade-one/iris/host"
+)
+
+func main() {
+	server := host.New("public", "index.html")
+	log.Println("Server running on http://localhost:8080")
+	log.Fatal(http.ListenAndServe(":8080", server))
+}
+```
+
+## Directory Structure
+
+```
+myapp/
+├── server.go           # Server code (above)
+└── public/
+    ├── index.html      # Entry point
+    ├── app.wasm        # Compiled WASM binary
+    └── wasm_exec.js    # Go WASM runtime
+```
+
+## Serving Static Files
+
+The server serves files from the specified public directory. Any request path maps directly to files:
+
+- `/` → `public/index.html`
+- `/app.wasm` → `public/app.wasm`
+- `/styles.css` → `public/styles.css`
+
+**SPA Fallback**: Unknown paths and directories fall back to `index.html`, enabling client-side routing.
+
+## WASM MIME Types
+
+The server automatically sets correct MIME types for all common file types:
+
+| Extension | MIME Type |
+|-----------|-----------|
+| `.wasm` | `application/wasm` |
+| `.html` | `text/html; charset=utf-8` |
+| `.js` | `application/javascript` |
+| `.css` | `text/css` |
+| `.json` | `application/json` |
+| `.svg` | `image/svg+xml` |
+
+This ensures browsers load WASM files correctly without manual configuration.
+
+## Compression
+
+Gzip compression is automatically applied to compressible content types when the client supports it:
+
+- HTML, CSS, JavaScript
+- JSON
+- WASM binaries
+- SVG images
+
+Binary assets (PNG, JPEG, etc.) are served uncompressed since they're already compressed.
+
+## Development vs Production
+
+### Development
+
+```go
+func main() {
+	server := host.New("public", "index.html")
+	http.ListenAndServe(":8080", server)
+}
+```
+
+Run with:
+```bash
+go run server.go
+```
+
+### Production
+
+For production, compile the server and run as a binary:
+
+```bash
+go build -o server ./server.go
+./server
+```
+
+Consider adding:
+- TLS termination (via reverse proxy or `http.ListenAndServeTLS`)
+- Environment-based port configuration
+- Graceful shutdown handling
+
+Example with TLS:
+```go
+func main() {
+	server := host.New("public", "index.html")
+	log.Fatal(http.ListenAndServeTLS(":443", "cert.pem", "key.pem", server))
+}
+```
+
+Example with reverse proxy (nginx):
+```nginx
+server {
+    listen 443 ssl;
+    server_name example.com;
+
+    location / {
+        proxy_pass http://localhost:8080;
+        proxy_set_header Host $host;
+    }
+}
+```