Fix instructions for mounting Sprite over SSHFS (#88)

Author: jbellerb

src/content/docs/working-with-sprites.mdx

@@ -232,7 +232,21 @@ These features are useful once you're comfortable.
 
 Use SSHFS to mount your Sprite and edit files with your local tools.
 
-**Install SSHFS first:**
+Sprites don't expose SSH directly—you'll need to install an SSH server on your 
+Sprite and tunnel the connection through `sprite proxy`. This keeps your Sprite 
+secure while still allowing local filesystem access.
+
+**Prepare an SSH server on your Sprite:**
+
+```bash
+# Install OpenSSH
+sudo apt install -y openssh-server
+
+# Create a service to automatically start it
+sprite-env services create sshd --cmd /usr/sbin/sshd
+```
+
+**Install SSHFS on your local machine:**
 
 ```bash
 # macOS
@@ -245,25 +259,42 @@ sudo apt-get install sshfs
 sudo dnf install fuse-sshfs
 ```
 
+**Authorize your SSH public keys:**
+
+```bash
+sprite exec mkdir -p .ssh
+sprite exec bash -c "echo '$(cat ~/.ssh/id_*.pub)' >> .ssh/authorized_keys"
+```
+
 **Add this helper to your shell config:**
 
 ```bash
 # Add to ~/.zshrc or ~/.bashrc
-sc() {
-  local sprite_name="${1:-$(sprite use)}"
-  local mount_point="/tmp/sprite-${sprite_name}"
+spritemount() {
+  local sprite_name="$1"
+  local mount_point="/tmp/sprite-mount"
   mkdir -p "$mount_point"
+  if pid=$(lsof -t -i :2000); then
+    read -rp "A Sprite is already mounted, unmount it? (y/n) " yn
+    [ "$yn" == "y" ] || return 1
+    kill $pid && umount "$mount_point"
+  fi
+  sprite proxy -s "$sprite_name" 2000:22 &
+  sleep 1  # wait for the proxy to start
   sshfs -o reconnect,ServerAliveInterval=15,ServerAliveCountMax=3 \
-    "sprite@${sprite_name}.sprites.dev:" "$mount_point"
-  cd "$mount_point"
+    "sprite@localhost:" -p 2000 "$mount_point"
+  cd "$mount_point" || return 1
 }
+
+# Mount the sprite with "spritemount my-sprite"
 ```
 
 **Unmount when done:**
 
 ```bash
-umount /tmp/sprite-my-sprite
-# macOS may need: diskutil umount /tmp/sprite-my-sprite
+umount /tmp/sprite-mount
+# macOS may need: diskutil umount /tmp/sprite-mount
+kill $(lsof -t -i:2000)
 ```
 
 ### Common Error Scenarios