PHY: レイアウトバリアントを木のノードとして導入し、ELC/IDXの扱いを決める

交換可能なキークラスタ(ISO Enter、スペース周りのキー数など)を、
VariantGroup / Variant の2ノードでPHYの木に表す。全バリアントのキーを
同時に持ち、単一の配置を要求する出力のときだけ1つ選んで畳む。

ELCは選択に関係なくsupersetを配線する。排他キー同士は同じ接続先を共有してよい。
IDXはキー番号の空間を1つに保ち、同じ接続先に配線された排他キーは
`order` の配列要素として同じ番号を共有する。

Journal: journal/2026-09-21-multi-layout.md

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JPCpuPv6hDN76RgNe2PsRR

phase1-json-schema.md

@@ -61,7 +61,8 @@ ELC・IDX・MAPはどれもPHYを参照する。ELCはIDXを参照せず、MAP
         "oneOf": [
           { "$ref": "#/$defs/key" },
           { "$ref": "#/$defs/cluster" },
-          { "$ref": "#/$defs/component" }
+          { "$ref": "#/$defs/component" },
+          { "$ref": "#/$defs/variantGroup" }
         ]
       }
     }
@@ -186,6 +187,58 @@ ELC・IDX・MAPはどれもPHYを参照する。ELCはIDXを参照せず、MAP
         }
       }
     },
+    "variantGroup": {
+      "type": "object",
+      "description": "Mutually exclusive layout alternatives. Children are variants only",
+      "required": ["type", "id", "name", "transform", "default", "children"],
+      "properties": {
+        "type": {
+          "type": "string",
+          "const": "variantGroup"
+        },
+        "id": { "type": "string" },
+        "name": {
+          "type": "string",
+          "description": "Heading shown for the choice in the editor"
+        },
+        "transform": { "$ref": "#/$defs/transform" },
+        "default": {
+          "type": "string",
+          "description": "id of the variant used when a single layout must be chosen"
+        },
+        "children": {
+          "type": "array",
+          "minItems": 2,
+          "description": "Display order",
+          "items": { "$ref": "#/$defs/variant" }
+        }
+      }
+    },
+    "variant": {
+      "type": "object",
+      "description": "One alternative. Appears only directly under a variantGroup. Carries no transform",
+      "required": ["type", "id", "name", "children"],
+      "properties": {
+        "type": {
+          "type": "string",
+          "const": "variant"
+        },
+        "id": { "type": "string" },
+        "name": { "type": "string" },
+        "children": {
+          "type": "array",
+          "description": "May be empty",
+          "items": {
+            "oneOf": [
+              { "$ref": "#/$defs/key" },
+              { "$ref": "#/$defs/cluster" },
+              { "$ref": "#/$defs/component" },
+              { "$ref": "#/$defs/variantGroup" }
+            ]
+          }
+        }
+      }
+    },
     "cluster": {
       "type": "object",
       "required": ["type", "id", "transform", "children"],
@@ -203,7 +256,8 @@ ELC・IDX・MAPはどれもPHYを参照する。ELCはIDXを参照せず、MAP
             "oneOf": [
               { "$ref": "#/$defs/key" },
               { "$ref": "#/$defs/cluster" },
-              { "$ref": "#/$defs/component" }
+              { "$ref": "#/$defs/component" },
+              { "$ref": "#/$defs/variantGroup" }
             ]
           }
         }
@@ -296,13 +350,60 @@ ELC・IDX・MAPはどれもPHYを参照する。ELCはIDXを参照せず、MAP
       ]
     },
     {
-      "type": "key",
-      "id": "k_iso_enter",
-      "profile": "standard",
-      "transform": { "x": 6, "y": 1, "rotation": 0 },
-      "size": { "w": 1.5, "h": 1, "x2": 0.25, "y2": 1, "w2": 1.25, "h2": 1 },
-      "switchOffset": { "x": 0, "y": 0.5 },
-      "labels": ["Enter"]
+      "type": "variantGroup",
+      "id": "vg_enter",
+      "name": "Enter",
+      "transform": { "x": 6, "y": 0, "rotation": 0 },
+      "default": "v_ansi",
+      "children": [
+        {
+          "type": "variant",
+          "id": "v_ansi",
+          "name": "ANSI",
+          "children": [
+            {
+              "type": "key",
+              "id": "k_ansi_bslash",
+              "profile": "standard",
+              "transform": { "x": 1, "y": 0, "rotation": 0 },
+              "size": { "w": 1.5, "h": 1 },
+              "labels": ["|", "\\"]
+            },
+            {
+              "type": "key",
+              "id": "k_ansi_enter",
+              "profile": "standard",
+              "transform": { "x": 0.25, "y": 1, "rotation": 0 },
+              "size": { "w": 2.25, "h": 1 },
+              "labels": ["Enter"]
+            }
+          ]
+        },
+        {
+          "type": "variant",
+          "id": "v_iso",
+          "name": "ISO",
+          "children": [
+            {
+              "type": "key",
+              "id": "k_iso_enter",
+              "profile": "standard",
+              "transform": { "x": 1, "y": 0, "rotation": 0 },
+              "size": { "w": 1.5, "h": 1, "x2": 0.25, "y2": 1, "w2": 1.25, "h2": 1 },
+              "switchOffset": { "x": 0, "y": 0.5 },
+              "labels": ["Enter"]
+            },
+            {
+              "type": "key",
+              "id": "k_iso_hash",
+              "profile": "standard",
+              "transform": { "x": 0.25, "y": 1, "rotation": 0 },
+              "size": { "w": 1, "h": 1 },
+              "labels": ["~", "#"]
+            }
+          ]
+        }
+      ]
     },
     {
       "type": "component",
@@ -345,8 +446,19 @@ ELC・IDX・MAPはどれもPHYを参照する。ELCはIDXを参照せず、MAP
       "type": "array",
       "uniqueItems": true,
       "items": {
-        "type": "string",
-        "description": "Reference to PHY layer key ID"
+        "oneOf": [
+          {
+            "type": "string",
+            "description": "Reference to PHY layer key ID"
+          },
+          {
+            "type": "array",
+            "minItems": 2,
+            "uniqueItems": true,
+            "items": { "type": "string" },
+            "description": "Mutually exclusive variant keys sharing this key number. They must be wired to the same terminals in ELC"
+          }
+        ]
       }
     }
   }