test(e2e): add ingress module e2e test suite

Verifies hostname→endpoint routing at the reverse-proxy tunnel
entrypoint. A public gost runs a tunnel handler with an ingress
mapping example.local→tunnel-UUID and an HTTP entrypoint; an internal
client binds a reverse tunnel forwarding to the echo server. A request
with a mapped Host is routed through the tunnel to the echo server,
while an unmapped Host matches no ingress rule and is rejected.

tests/e2e/testdata/ingress/client.yaml

@@ -0,0 +1,37 @@
+# Internal client behind NAT: binds a reverse tunnel (tunnel.id matches the
+# server's ingress endpoint) and forwards tunneled connections to the echo
+# server. The tunnel server is reached via chain-0's tunnel connector.
+#
+# service-1 is a dummy TCP listener on a fixed port; the rtcp reverse-tunnel
+# listener binds remotely through the chain and opens no local port, so this
+# gives the e2e harness a stable port to wait on.
+services:
+  - name: service-0
+    addr: ":0"
+    handler:
+      type: rtcp
+    listener:
+      type: rtcp
+      chain: chain-0
+    forwarder:
+      nodes:
+        - addr: tcp-echo:5678
+
+  - name: service-1
+    addr: ":8423"
+    handler:
+      type: http
+    listener:
+      type: tcp
+
+chains:
+  - name: chain-0
+    hops:
+      - nodes:
+        - addr: gost-server:8421
+          connector:
+            type: tunnel
+            metadata:
+              tunnel.id: 6be39003-f4fa-49e4-a6ef-1997684d160e
+          dialer:
+            type: tcp