fix(nodes): stop multi-attached client traffic inflating across node inbounds

Xray counts client traffic globally per email, so a client attached to
several of a node's inbounds has its single shared counter copied onto
every inbound by the node's enriched inbound list. When those copies
diverge (legacy per-inbound rows surviving a v3.2.x->v3.3.x upgrade, or
any drift) the per-inbound delta loop read the lower sibling as a
node-counter reset and re-added its full value, inflating the client far
past real usage (#5274).

Fold each email to its per-field node-wide max before the delta loop so
every occurrence is equal: the per-email baseline dedup then holds and
the reset clamp never misfires.

internal/util/link/outbound_helpers_test.go

@@ -15,9 +15,9 @@ func TestDefaultPort(t *testing.T) {
 	}{
 		{"", 443, 443},
 		{"8080", 443, 8080},
-		{"0", 443, 443},     // non-positive falls back
-		{"-1", 443, 443},    // negative falls back
-		{"abc", 443, 443},   // unparseable falls back
+		{"0", 443, 443},   // non-positive falls back
+		{"-1", 443, 443},  // negative falls back
+		{"abc", 443, 443}, // unparseable falls back
 		{"65535", 443, 65535},
 	}
 	for _, c := range cases {