feat: remove network_mode host for standalone WebRTC (#864)

* feat: remove network_mode host for standalone by fixing WebRTC port range and ICE candidates

aioice hardcodes bind(addr, 0) for ICE UDP sockets, making port mapping
impossible in Docker bridge networking. This adds two env-var-gated
mechanisms to replace network_mode: host:

1. WEBRTC_PORT_RANGE (e.g. "50000-50100"): monkey-patches aioice to bind
   UDP sockets within a known range, so they can be mapped in Docker.

2. WEBRTC_HOST (e.g. "host.docker.internal"): rewrites container-internal
   IPs in SDP answers with the Docker host's real IP, so LAN clients can
   reach the ICE candidates.

Both default to None — no effect on existing deployments.

* fix: do not attempt sidecar to detect host ip, use the standalone script to figure out the external ip and use it

* style: reformat

---------

Co-authored-by: tito <tito@titos-Mac-Studio.local>

scripts/setup-standalone.sh

@@ -104,6 +104,29 @@ rebuild_images() {
     done
 }
 
+detect_lan_ip() {
+    # Returns the host's LAN IP — used for WebRTC ICE candidate rewriting.
+    case "$OS" in
+        Darwin)
+            # Try common interfaces: en0 (Wi-Fi), en1 (Ethernet)
+            for iface in en0 en1 en2 en3; do
+                local ip
+                ip=$(ipconfig getifaddr "$iface" 2>/dev/null || true)
+                if [[ -n "$ip" ]]; then
+                    echo "$ip"
+                    return
+                fi
+            done
+            ;;
+        Linux)
+            ip route get 1.1.1.1 2>/dev/null | sed -n 's/.*src \([^ ]*\).*/\1/p'
+            return
+            ;;
+    esac
+    # Fallback — empty means "not detected"
+    echo ""
+}
+
 wait_for_url() {
     local url="$1" label="$2" retries="${3:-30}" interval="${4:-2}"
     for i in $(seq 1 "$retries"); do
@@ -262,6 +285,17 @@ ENVEOF
     env_set "$SERVER_ENV" "LLM_MODEL" "$MODEL"
     env_set "$SERVER_ENV" "LLM_API_KEY" "not-needed"
 
+    # WebRTC: detect LAN IP for ICE candidate rewriting (bridge networking)
+    local lan_ip
+    lan_ip=$(detect_lan_ip)
+    if [[ -n "$lan_ip" ]]; then
+        env_set "$SERVER_ENV" "WEBRTC_HOST" "$lan_ip"
+        ok "WebRTC host IP: $lan_ip"
+    else
+        warn "Could not detect LAN IP — WebRTC recording from other devices may not work"
+        warn "Set WEBRTC_HOST=<your-lan-ip> in server/.env manually"
+    fi
+
     ok "Standalone vars set (LLM_URL=$LLM_URL_VALUE)"
 }