suite check: направление ссылок внутри темы проверяется во всём документе

- ссылка на слой своей темы с объявленной осью — ошибка где угодно, а не только
  в норме: гарантированно присутствует в копии один базовый слой
- ссылки на чужую тему вне нормы остаются разрешёнными по META-20

internal/check/layers_test.go

@@ -160,7 +160,22 @@ func TestLayeredChecks(t *testing.T) {
 				"**ДОЛЖЕН.** Момент времени записывается с суффиксом Z.",
 				"**ДОЛЖЕН.** Момент времени записывается с суффиксом Z, как требует GTIM-1.", 1)
 		},
-		want: "a layer of its own topic but not the base one",
+		want: "points at a layer of this topic that is not the base one",
+	}, {
+		name: "rationale of the base layer references a layer above it",
+		setup: func(f files) {
+			f["conventions/arch/time.md"] = strings.Replace(archTime,
+				"**ПОЧЕМУ.** Без явного смещения не видно, в какой зоне запись сделана.",
+				"**ПОЧЕМУ.** Без явного смещения не видно зоны; в Go это выражает GTIM-1.", 1)
+		},
+		want: "points at a layer of this topic that is not the base one",
+	}, {
+		name: "a section outside any rule references a layer above",
+		setup: func(f files) {
+			f["conventions/arch/time.md"] = archTime +
+				"\n## Связано\n\nРеализация на Go — GTIM-1.\n"
+		},
+		want: "points at a layer of this topic that is not the base one",
 	}}
 
 	for _, tc := range cases {
@@ -220,7 +235,7 @@ func TestNoFalsePositives(t *testing.T) {
 		name: "a stub of a retired rule with a date and a reason",
 		setup: func(f files) {
 			f["conventions/arch/time.md"] = archTime +
-				"\n### TIME-2. Ширина строки фиксируется\n\n**СНЯТО 2026-07-26.** Правило переехало в GTIM-1.\n"
+				"\n### TIME-2. Ширина строки фиксируется\n\n**СНЯТО 2026-07-26.** Ширина следует из TIME-1 и отдельного правила не требует.\n"
 		},
 	}, {
 		name: "a scenario block in the suite's own vocabulary",
@@ -235,6 +250,26 @@ func TestNoFalsePositives(t *testing.T) {
 				"**ПОЧЕМУ.** Без явного смещения не видно, в какой зоне запись сделана.",
 				"**ПОЧЕМУ.** Условие `WHERE a AND b OR c` сортировку не спасает.", 1)
 		},
+	}, {
+		name: "a rationale references a foreign topic, which META-20 allows",
+		setup: func(f files) {
+			f["conventions/lang/go/time.md"] = strings.Replace(goTime,
+				"**ПОЧЕМУ.** Единая точка даёт гарантированный UTC.",
+				"**ПОЧЕМУ.** Единая точка даёт гарантированный UTC; тот же довод стоит за SLOG-1.", 1)
+		},
+	}, {
+		name: "a section outside any rule references a foreign topic",
+		setup: func(f files) {
+			f["conventions/lang/go/time.md"] = goTime +
+				"\n## Связано\n\nКонвенция logging, правило SLOG-1.\n"
+		},
+	}, {
+		name: "a layer references the base layer of its topic outside a norm",
+		setup: func(f files) {
+			f["conventions/lang/go/time.md"] = strings.Replace(goTime,
+				"**ПОЧЕМУ.** Единая точка даёт гарантированный UTC.",
+				"**ПОЧЕМУ.** Единая точка даёт гарантированный UTC, чего и требует TIME-1.", 1)
+		},
 	}, {
 		name: "the single document without a topic is the one the suite governs itself by",
 		setup: func(f files) {

internal/check/spread.go

@@ -19,7 +19,8 @@ func checkSpread(s *suite.Suite, d *doc.Document, rep *Report) {
 	checkExtends(s, d, rep)
 	checkMechanized(s, d, rep)
 	checkCanonPaths(s, d, rep)
-	checkForeignTopicPrefix(s, d, rep)
+	checkForeignTopicInNorm(s, d, rep)
+	checkOwnTopicLayerRefs(s, d, rep)
 }
 
 // checkTopic reconciles the topic from the front matter with the manifest
@@ -151,13 +152,16 @@ func checkCanonPaths(s *suite.Suite, d *doc.Document, rep *Report) {
 	}
 }
 
-// checkForeignTopicPrefix looks for the prefix of a foreign topic inside a norm
+// checkForeignTopicInNorm looks for the prefix of a foreign topic inside a norm
 // block (META-20). The norm of a rule must be executable holding this one file:
 // a repository subscribes to an arbitrary subset of the conventions, and it has
-// no dependency graph by construction. The prefix of the base layer of its own
+// no dependency graph by construction.
-// topic is allowed there (META-24) — an assembled file starts with that layer
+//
-// whatever language and stack were chosen.
+// Outside a norm such a reference is lawful and stays unchecked. A rationale
-func checkForeignTopicPrefix(s *suite.Suite, d *doc.Document, rep *Report) {
+// that loses its addressee degrades honestly — the cross-check goes, the
+// meaning stays — while a norm missing a neighbouring file becomes unenforceable
+// in silence.
+func checkForeignTopicInNorm(s *suite.Suite, d *doc.Document, rep *Report) {
 	own := s.Prefix(d)
 	for _, r := range d.Rules {
 		for _, norm := range r.Norms() {
@@ -166,21 +170,44 @@ func checkForeignTopicPrefix(s *suite.Suite, d *doc.Document, rep *Report) {
 					continue
 				}
 				target, ok := s.ByPrefix[ref.Prefix]
-				if !ok {
+				if !ok || target.Front.Topic == d.Front.Topic {
 					continue
 				}
-				if target.Front.Topic != d.Front.Topic {
+				rep.Errorf(Spread, d.Path, ref.Line,
-					rep.Errorf(Spread, d.Path, ref.Line,
+					"the norm of %s refers to %s from the foreign topic %q: only the rationale looks outward",
-						"the norm of %s refers to %s from the foreign topic %q: only the rationale looks outward",
+					r.ID(), ref.Text, target.Front.Topic)
-						r.ID(), ref.Text, target.Front.Topic)
-					continue
-				}
-				if target.Front.Axis() {
-					rep.Errorf(Spread, d.Path, ref.Line,
-						"the norm of %s refers to %s, a layer of its own topic but not the base one: that layer reaches the copy through the manifest, so there is no guarantee it stands nearby",
-						r.ID(), ref.Text)
-				}
 			}
 		}
 	}
 }
+
+// checkOwnTopicLayerRefs holds the direction of references inside one topic:
+// only the base layer may be pointed at, and from anywhere in the document
+// rather than from the norm alone.
+//
+// Guaranteed to stand in the copy is exactly one layer of a topic — the base
+// one; it goes in whatever language and stack were chosen (META-24). The order
+// of assembly, base then language then stack, is the order of concatenation and
+// not a chain of dependency: a consumer is free to take stack=htmx with
+// lang=python, so a stack layer has no claim on a language layer either.
+//
+// The reason reaches past dangling links. The base layer is the text that has
+// to hold for every language and every stack; a rationale of its that needs a
+// rule of the Go layer to explain itself is the specific leaking into the
+// shared, and the reasoning belongs in that layer instead. The base layer is
+// therefore left no way to point at a layer above it at all — by design.
+func checkOwnTopicLayerRefs(s *suite.Suite, d *doc.Document, rep *Report) {
+	own := s.Prefix(d)
+	for _, ref := range refsIn(d, d.Body, d.Len()) {
+		if ref.Prefix == own || strings.HasPrefix(ref.Prefix, "X") {
+			continue
+		}
+		target, ok := s.ByPrefix[ref.Prefix]
+		if !ok || target.Front.Topic != d.Front.Topic || !target.Front.Axis() {
+			continue
+		}
+		rep.Errorf(Spread, d.Path, ref.Line,
+			"the reference %s points at a layer of this topic that is not the base one: only the base layer is guaranteed to stand in a copy, and a rule that needs this one belongs in that layer",
+			ref.Text)
+	}
+}