ws: read the all-ICE declaration from the offer envelope, drop the proto field

Companion to hbb_common 68d2729: the full-ICE declaration now lives as
an `ice_policy: "all"` key inside the webrtc:// envelope, so the request
assembly no longer sets webrtc_all_ice and the controlled side asks the
envelope (endpoint_declares_all_ice) instead of a PunchHole field. The
rendezvous server carries the offer opaquely — no forwarding to keep in
sync. Skew behavior is unchanged: an unmarked or unparseable envelope
reads as the old Relay-only semantics.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ExUfAkYbq8UC9pQCiLy8TQ

src/client.rs

@@ -612,7 +612,8 @@ impl Client {
     /// is configured, so skip building a guaranteed-dead pc + STUN/TURN gathering + answerer
     /// signaling in that case. WebSocket-forced relay is deliberately NOT policy: ws only
     /// tunnels the signaling/relay legs, so the offer keeps full ICE and may land a direct
-    /// connection - the flagship path for ws deployments (`webrtc_all_ice` tells the peer).
+    /// connection - the flagship path for ws deployments (the offer envelope's `ice_policy`
+    /// key tells the peer).
     /// When policy relay *and* TURN are configured, WebRTC via TURN is a valid "relayed" path:
     /// `connect` keeps a WebRTC win instead of replacing it with the RustDesk relay, and the
     /// RelayResponse path races it without a P2P preference delay. Any request carrying an offer
@@ -888,10 +889,10 @@ impl Client {
             force_relay: interface.is_force_relay(),
             socket_addr_v6: ipv6.1.unwrap_or_default(),
             switch_code,
+            // The offer's envelope itself declares its ICE policy (`ice_policy: "all"` under
+            // pure ws), telling the controlled side its answer may gather every candidate
+            // type despite force_relay instead of requiring TURN.
             webrtc_sdp_offer: webrtc_sdp_offer.clone(),
-            // Full-ICE offer despite force_relay (ws transport): tells the controlled side
-            // its answer may gather every candidate type instead of requiring TURN.
-            webrtc_all_ice: !webrtc_sdp_offer.is_empty() && !interface.is_policy_relay(),
             ..Default::default()
         });
         let webrtc_session_key = webrtc_offerer

src/rendezvous_mediator.rs

@@ -849,11 +849,13 @@ impl RendezvousMediator {
         // and STUN bypass the proxy and leak the real IP. WebSocket mode does NOT disable it —
         // ws only tunnels the signaling/relay legs to the server, classic punching stays forced
         // to relay (`relay` above), and the answer rides the RelayResponse, leaving ICE as the
-        // only P2P path there. force_relay depends on why it was set: with webrtc_all_ice the
+        // only P2P path there. force_relay depends on why it was set, and the offer's envelope
-        // controller's relay is transport-forced (ws) and its offer carries every candidate
+        // says which: an `ice_policy: "all"` declaration means the controller's relay is
-        // type, so answer with full ICE and let a direct pair form; without it the offer is
+        // transport-forced (ws) and its offer carries every candidate type, so answer with
-        // Relay-only ICE by policy, viable (and answerable) only through TURN.
+        // full ICE and let a direct pair form; without it the offer is Relay-only ICE by
-        let webrtc_relay_only = ph.force_relay && !ph.webrtc_all_ice;
+        // policy, viable (and answerable) only through TURN.
+        let webrtc_relay_only = ph.force_relay
+            && !WebRTCStream::endpoint_declares_all_ice(&ph.webrtc_sdp_offer);
         let webrtc_viable = !ph.webrtc_sdp_offer.is_empty()
             && !Config::is_proxy()
             && (!webrtc_relay_only || WebRTCStream::has_turn_server());