@@ -2206,6 +2206,13 @@
         "toMajor": 18,
         "rationale": "ADR-0032 Decision 3 fixes one template delimiter, double braces, and deletes the single brace: it collides with CEL map literals, and an author who meets both dialects in one flow mixes them. The 17.x interpolator and the template engine render the same text for a path holding a string, a number, a boolean, null, an absent key or variable, an ISO date string, an object or an array, but not for every value — a Date rendered JSON-quoted under the interpolator and as its ISO text under the engine, and a screen title, screen description or end message that was one token holding an object, an array or a Date rendered String(value) — so no conversion is lossless (ADR-0087 D2) and none is applied. Arithmetic, function calls, the date macros and the run-user paths have no hole spelling: a hole is a path with a formatter, never logic. A flow carrying a single-brace token in a text slot is refused at registration, by objectstack validate and by the node contract; a stored flow carrying one is skipped at boot with a warn naming it."
       },
+      {
+        "surface": "flows[].nodes[].config of a notify node (title, message), a screen node (title, description) and an end node (message) — a string, or the source of a template envelope, carrying a double-brace hole whose root is a dollar-named variable the flow engine does not bind, such as {{ $User.Id }}",
+        "replacement": "a variable the run has, written as a hole. The run user is computed first, with an assignment node whose value slot still reads the run-user path (assignments: { by: '{$User.Id}' }), then written as {{ by }}. A variable the flow binds itself (a declared variable, an assignment target, an outputVariable, a try_catch errorVariable) is named without the dollar sign and written as {{ caught.message }}. The engine's own variables stay holes: {{ $error.message }}, {{ $record.name }}, {{ $runId }}, {{ $flowName }}, {{ $flowLabel }}, and a flat-graph loop's {{ $loopItems }} / {{ $loopIndex }}",
+        "migrationId": "flow-text-slot-unbound-dollar-root-refused",
+        "toMajor": 18,
+        "rationale": "The dollar-named variables are the flow engine's own: it binds $record, $runId, $flowName, $flowLabel and $error, and a flat-graph loop binds $loopItems and $loopIndex. A hole over any other dollar name answers to no variable — {{ $User.Id }} looks like the run user and is not one, since the run user has no hole spelling. In 17.x the slot was a plain string read by the single-brace interpolator, which substituted the inner token and left a literal brace on each side; the 18 text slots render holes through the template engine, where such a hole renders nothing and the run reports success. It is now refused by the node contract, at registration and by objectstack validate, with the remedy its single-brace spelling gets; a stored flow carrying one is skipped at boot with a warn naming it. No D2 conversion exists: what the author meant the hole to read is not in the flow, and the template engine binds no new variable to answer it."
+      },
       {
         "surface": "the record and previous roots a record-change flow receives — a password or secret field, and an internal field, of the triggering record, on every object",
         "replacement": "read a credential through a privileged binder — the flow credential channel for an http node's signing secret, or a privileged server-side read such as the engine's resolveSecretField — never off `record` or `previous`; on those roots a set credential-class field now reads as the mask `SECRET_MASK`, an unset one as null, and an `internal: true` field is absent",
@@ -5795,6 +5802,13 @@
           "toMajor": 18,
           "rationale": "ADR-0032 Decision 3 fixes one template delimiter, double braces, and deletes the single brace: it collides with CEL map literals, and an author who meets both dialects in one flow mixes them. The 17.x interpolator and the template engine render the same text for a path holding a string, a number, a boolean, null, an absent key or variable, an ISO date string, an object or an array, but not for every value — a Date rendered JSON-quoted under the interpolator and as its ISO text under the engine, and a screen title, screen description or end message that was one token holding an object, an array or a Date rendered String(value) — so no conversion is lossless (ADR-0087 D2) and none is applied. Arithmetic, function calls, the date macros and the run-user paths have no hole spelling: a hole is a path with a formatter, never logic. A flow carrying a single-brace token in a text slot is refused at registration, by objectstack validate and by the node contract; a stored flow carrying one is skipped at boot with a warn naming it."
         },
+        {
+          "surface": "flows[].nodes[].config of a notify node (title, message), a screen node (title, description) and an end node (message) — a string, or the source of a template envelope, carrying a double-brace hole whose root is a dollar-named variable the flow engine does not bind, such as {{ $User.Id }}",
+          "replacement": "a variable the run has, written as a hole. The run user is computed first, with an assignment node whose value slot still reads the run-user path (assignments: { by: '{$User.Id}' }), then written as {{ by }}. A variable the flow binds itself (a declared variable, an assignment target, an outputVariable, a try_catch errorVariable) is named without the dollar sign and written as {{ caught.message }}. The engine's own variables stay holes: {{ $error.message }}, {{ $record.name }}, {{ $runId }}, {{ $flowName }}, {{ $flowLabel }}, and a flat-graph loop's {{ $loopItems }} / {{ $loopIndex }}",
+          "migrationId": "flow-text-slot-unbound-dollar-root-refused",
+          "toMajor": 18,
+          "rationale": "The dollar-named variables are the flow engine's own: it binds $record, $runId, $flowName, $flowLabel and $error, and a flat-graph loop binds $loopItems and $loopIndex. A hole over any other dollar name answers to no variable — {{ $User.Id }} looks like the run user and is not one, since the run user has no hole spelling. In 17.x the slot was a plain string read by the single-brace interpolator, which substituted the inner token and left a literal brace on each side; the 18 text slots render holes through the template engine, where such a hole renders nothing and the run reports success. It is now refused by the node contract, at registration and by objectstack validate, with the remedy its single-brace spelling gets; a stored flow carrying one is skipped at boot with a warn naming it. No D2 conversion exists: what the author meant the hole to read is not in the flow, and the template engine binds no new variable to answer it."
+        },
         {
           "surface": "the record and previous roots a record-change flow receives — a password or secret field, and an internal field, of the triggering record, on every object",
           "replacement": "read a credential through a privileged binder — the flow credential channel for an http node's signing secret, or a privileged server-side read such as the engine's resolveSecretField — never off `record` or `previous`; on those roots a set credential-class field now reads as the mask `SECRET_MASK`, an unset one as null, and an `internal: true` field is absent",