guestlink v1: self-hosted guest line (Cleanfeed replacement)

Go + Pion + libopus. One guest, live audio both ways, anonymous chat.
README for this version was not preserved; see the next commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

go.mod

@@ -0,0 +1,33 @@
+module guestlink
+
+go 1.26.8
+
+require (
+	github.com/gorilla/websocket v1.5.3
+	github.com/pion/ice/v4 v4.4.8
+	github.com/pion/interceptor v0.1.51
+	github.com/pion/rtp v1.10.6
+	github.com/pion/stun/v4 v4.0.1
+	github.com/pion/webrtc/v4 v4.2.26
+	golang.org/x/sys v0.41.0
+	gopkg.in/hraban/opus.v2 v2.0.0-20230925203106-0188a62cb302
+)
+
+require (
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/pion/datachannel v1.6.3 // indirect
+	github.com/pion/dtls/v3 v3.1.15 // indirect
+	github.com/pion/logging v0.2.4 // indirect
+	github.com/pion/mdns/v2 v2.2.2 // indirect
+	github.com/pion/randutil v0.1.0 // indirect
+	github.com/pion/rtcp v1.2.20 // indirect
+	github.com/pion/sctp v1.12.0 // indirect
+	github.com/pion/sdp/v3 v3.0.20 // indirect
+	github.com/pion/srtp/v3 v3.1.3 // indirect
+	github.com/pion/transport/v5 v5.1.4 // indirect
+	github.com/pion/turn/v5 v5.1.3 // indirect
+	github.com/wlynxg/anet v0.0.5 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
+	golang.org/x/net v0.50.0 // indirect
+	golang.org/x/time v0.14.0 // indirect
+)