SD-M3: every other seat at the seat list's grain, in its reading order (ADR 0613 §2)

Converted mechanically from mesh-sdk's compiled list at 5a38a12 by a program kept out of the repository; the three new
registry seats follow npm-package-registry, operator-channel the mesh's own seats.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

format/seat-definition.schema.json

@@ -118,7 +118,7 @@
         "properties": {
           "name": {
             "type": "string",
-            "pattern": "^[a-z][a-z0-9-]*$"
+            "pattern": "^[a-z][a-z0-9-]*(\\.[a-z][a-z0-9-]*)*$"
           },
           "subject": {
             "type": "string"
@@ -381,7 +381,7 @@
           },
           "of": {
             "type": "string",
-            "pattern": "^(verb:[a-z][a-z0-9-]*\\.(input|answer)|accept:[a-z][a-z0-9-]*|event:[a-z][a-z0-9-]*|holder-event:[a-z][a-z0-9-]*)$"
+            "pattern": "^(verb:[a-z][a-z0-9-]*\\.(input|answer)|accept:[a-z][a-z0-9-]*|event:[a-z][a-z0-9-]*|holder-event:[a-z][a-z0-9-]*(\\.[a-z][a-z0-9-]*)*)$"
           },
           "subject": {
             "type": "string"