K16 (notify every channel): notify may ask a message sent on every channel

operator-channel's notify takes every-channel, which the router sends on every channel's send, as a break-glass
act is announced; the teller tells widens, recovery-merged and forge-made through it. A fixture reads the input.
Generated code waits for K21.

Builds: design 47 G §514

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

operator-and-conversation/seats/operator-channel/fixtures/verbs.json

@@ -0,0 +1,13 @@
+[
+  {
+    "name": "notify asks the message sent on every channel",
+    "of": "verb:notify.input",
+    "given": {
+      "key": "widens.mesh-delivery",
+      "severity": "warning",
+      "summary": "a change widens what a module may do",
+      "subject": "mesh-delivery",
+      "every-channel": true
+    }
+  }
+]

operator-and-conversation/seats/operator-channel/seat.json

@@ -78,6 +78,10 @@
           "clear": {
             "type": "boolean",
             "description": "it is over"
+          },
+          "every-channel": {
+            "type": "boolean",
+            "description": "send it on every channel's send, as a break-glass act is announced, not on the operator's chosen channel alone (design 47 G 514)"
           }
         }
       },