fix(sub): stop the subscription from 500ing on valid-but-unusual stream settings

The raw share-link generators used unchecked type assertions and unguarded
array indexing: an empty Reality shortIds/serverNames array (random.Num(0)
panics), a tcp-http header with no request block or an empty request.path, a
grpc block missing its keys, empty stream settings, and a non-string Host
header all panicked mid-generation. Because getSubs loops every client's link
with no recover, one such client 500s the entire subscription for everyone. The
sibling JSON, Clash and frontend generators already guard these; make the raw
generators match with comma-ok assertions and length checks.

internal/sub/sub_panic_test.go

@@ -0,0 +1,43 @@
+package sub
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+)
+
+// A subscription is built by iterating every client's share link with no
+// recover(), so any panic in the link generators 500s the whole subscription
+// for every client. Valid-but-unusual stream settings (an empty Reality
+// shortIds/serverNames array, a tcp-http header with no request, a grpc block
+// missing its keys) must therefore produce a link, not a panic.
+func TestGetSubsToleratesUnusualStreamSettings(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	cases := []struct {
+		name   string
+		stream string
+	}{
+		{"reality empty arrays", `{"network":"tcp","security":"reality","realitySettings":{"serverNames":[],"shortIds":[],"settings":{"publicKey":"pk"}}}`},
+		{"tcp http missing request", `{"network":"tcp","security":"none","tcpSettings":{"header":{"type":"http","response":{"headers":{}}}}}`},
+		{"tcp http empty path", `{"network":"tcp","security":"none","tcpSettings":{"header":{"type":"http","request":{"path":[]}}}}`},
+		{"grpc missing keys", `{"network":"grpc","security":"none","grpcSettings":{}}`},
+		{"empty stream settings", `{}`},
+	}
+
+	for i, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			seedSubDB(t)
+			subId := fmt.Sprintf("s%d", i)
+			seedSubInbound(t, subId, fmt.Sprintf("t%d", i), 46000+i, 1, tc.stream)
+
+			links, _, _, _, err := NewSubService("").GetSubs(subId, "req.example.com")
+			if err != nil {
+				t.Fatalf("GetSubs errored: %v", err)
+			}
+			if len(links) != 1 {
+				t.Fatalf("expected 1 share link, got %d", len(links))
+			}
+		})
+	}
+}