Carry the fence depth through blockquotes and lists, and split the block spelling from it

corpus/README.md

@@ -1,6 +1,6 @@
 # The corpus
 
-One directory per contract kind:
+One directory per contract kind, each landing with its milestone:
 
 - `round-trip/` — `<name>.json` + `<name>.md`: the markdown `adfToMarkdown` must emit for that
   document, byte for byte, and that `markdownToAdf` must read back to it (AGENTS.md §2). Grouped
@@ -10,8 +10,8 @@ One directory per contract kind:
 - `errors/` — `<name>.md`: markdown input that must not convert. A `<name>.error` beside it
   pins which error.
 - `unspellable/` — `<name>.json`: ADF `adfToMarkdown` must refuse, the `ConvertErrorCode` in the
-  `<name>.error` beside it. A maintainer decision (`todo.md`) moves a document from here to
-  `round-trip/`.
+  `<name>.error` beside it. Two populations live here: refusals that stay contract, and documents
+  a maintainer decision (`todo.md`) moves to `round-trip/`.
 - `real-payloads/` — `<name>.json`: sanitized live ADF, round-tripped ADF→markdown→ADF. No
   expected markdown.
 

corpus/round-trip/block-nodes/container-crossing.json

@@ -0,0 +1,77 @@
+{
+  "content": [
+    {
+      "attrs": {
+        "panelType": "info"
+      },
+      "content": [
+        {
+          "content": [
+            {
+              "content": [
+                {
+                  "attrs": {
+                    "panelType": "warning"
+                  },
+                  "content": [
+                    {
+                      "content": [
+                        {
+                          "text": "Check the torque before signing off.",
+                          "type": "text"
+                        }
+                      ],
+                      "type": "paragraph"
+                    }
+                  ],
+                  "type": "panel"
+                }
+              ],
+              "type": "listItem"
+            },
+            {
+              "content": [
+                {
+                  "content": [
+                    {
+                      "text": "Plain item.",
+                      "type": "text"
+                    }
+                  ],
+                  "type": "paragraph"
+                }
+              ],
+              "type": "listItem"
+            }
+          ],
+          "type": "bulletList"
+        },
+        {
+          "content": [
+            {
+              "attrs": {
+                "title": "Full build log"
+              },
+              "content": [
+                {
+                  "content": [
+                    {
+                      "text": "The build ran for 11 minutes.",
+                      "type": "text"
+                    }
+                  ],
+                  "type": "paragraph"
+                }
+              ],
+              "type": "expand"
+            }
+          ],
+          "type": "blockquote"
+        }
+      ],
+      "type": "panel"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/block-nodes/container-crossing.md

@@ -0,0 +1,10 @@
+::::panel info
+- :::panel warning
+  Check the torque before signing off.
+  :::
+- Plain item.
+
+> :::expand {title="Full build log"}
+> The build ran for 11 minutes.
+> :::
+::::