fix(coach): keep the chart on "as a table" so the chart is offered back

"As a table" used to drop the table's chart, so the reply offered no way
back to it. The copied table now keeps its chart and carries view: table,
which the panel opens on the table (the chart one tap away on the toggle)
and the chips read to offer "as a chart". show_result with view table
does the same. The field is optional on the result metadata; a client
that ignores it shows the chart first as before.

docs/api/openapi.yaml

@@ -50775,6 +50775,11 @@ components:
             - messageId
             - ref
           additionalProperties: false
+        view:
+          description: "`table` when the answer asked for the table view of a table that has a chart; the chart stays for the
+            toggle. Absent: the chart shows first when there is one."
+          type: string
+          const: table
       required:
         - ref
         - source
@@ -51074,6 +51079,11 @@ components:
             - messageId
             - ref
           additionalProperties: false
+        view:
+          description: "`table` when the answer asked for the table view of a table that has a chart; the chart stays for the
+            toggle. Absent: the chart shows first when there is one."
+          type: string
+          const: table
         columns:
           type: array
           items: