clarify some missing options in fetch

Author: vhess

README.md

@@ -665,7 +665,7 @@ The following table shows which configuration options are compatible with differ
 |--------|-------------------|---------------|--------|
 | `target` | ✅ | ✅ | Core option, works in both paths |
 | `forward` | ✅ | ✅ | Core option, works in both paths |
-| `agent` | ✅ | ❌ | Native agents only, use `fetch.dispatcher` instead |
+| `agent` | ✅ | ❌ | Native agents only |
 | `ssl` | ✅ | ✅ | HTTPS server configuration |
 | `ws` | ✅ | ❌ | WebSocket proxying uses native path only |
 | `xfwd` | ✅ | ✅ | X-Forwarded headers |
@@ -674,8 +674,8 @@ The following table shows which configuration options are compatible with differ
 | `prependPath` | ✅ | ✅ | Path manipulation |
 | `ignorePath` | ✅ | ✅ | Path manipulation |
 | `localAddress` | ✅ | ✅ | Local interface binding |
-| `changeOrigin` | ✅ | ✅ | Host header rewriting |
-| `preserveHeaderKeyCase` | ✅ | ✅ | Header case preservation |
+| `changeOrigin` | ✅ | ❌ | Host header rewriting |
+| `preserveHeaderKeyCase` | ✅ | ❌ | Header case preservation |
 | `auth` | ✅ | ✅ | Basic authentication |
 | `hostRewrite` | ✅ | ✅ | Redirect hostname rewriting |
 | `autoRewrite` | ✅ | ✅ | Automatic redirect rewriting |
@@ -693,7 +693,7 @@ The following table shows which configuration options are compatible with differ
 | `fetch` | ❌ | ✅ | Fetch-specific configuration |
 
 **Notes:**
-- ¹ `secure` is not directly supported in the fetch path. Instead, use `fetch.dispatcher` with `{connect: {rejectUnauthorized: false}}` to disable SSL certificate verification (e.g., for self-signed certificates).
+- ¹ `secure` is not directly supported in the fetch path. Instead, use a custom dispatcher with `{rejectUnauthorized: false}` to disable SSL certificate verification (e.g., for self-signed certificates).
 
 **Code Path Selection:**
 - **Native Path**: Used by default, supports HTTP/1.1 and WebSockets