test(12.2-05): prove relation child and protected file scoping through the router

- acme.deferred fixture plugin over testdata/deferred (test-only), two
  controllers, recording Form and Relation hooks, two admins
- TestRelationChildScope*: every child route answers 404 for another
  parent, a hidden parent and another admin's pending child, changes
  nothing; undeclared toolbar buttons 403 before SQL; pivot whitelist
- TestProtectedFile*: foreign, pending and public files 404; only jpeg,
  png, gif and webp inline; nosniff, no-store and sandbox CSP everywhere

modules/cabana/testdata/deferred/models/gadget/columns.yaml

@@ -0,0 +1,10 @@
+columns:
+    name:
+        label: Name
+        searchable: true
+    released_on:
+        label: Released on
+        type: date
+    opens_at:
+        label: Opens at
+        type: time

modules/cabana/testdata/deferred/models/gadget/fields.yaml

@@ -0,0 +1,37 @@
+fields:
+    name:
+        label: Name
+        type: text
+        required: true
+    released_on:
+        label: Released on
+        type: datepicker
+        mode: date
+        minDate: 2000-01-01
+        maxDate: 2030-12-31
+    starts_at:
+        label: Starts at
+        type: datepicker
+        mode: datetime
+        minDate: 2000-01-01
+        maxDate: 2030-12-31
+    opens_at:
+        label: Opens at
+        type: datepicker
+        mode: time
+    members:
+        type: relation-manager
+        relation: members
+    parts:
+        type: relation-manager
+        relation: parts
+    photos:
+        label: Photos
+        type: fileupload
+        mode: image
+        maxFiles: 3
+    manual:
+        label: Manual
+        type: fileupload
+        fileTypes: [pdf, png, svg, txt, html]
+        useCaption: true

modules/cabana/testdata/deferred/models/gadget/locked_fields.yaml

@@ -0,0 +1,15 @@
+fields:
+    name:
+        label: Name
+        type: text
+        required: true
+    members:
+        type: relation-manager
+        relation: members
+    parts:
+        type: relation-manager
+        relation: parts
+    manual:
+        label: Manual
+        type: fileupload
+        required: true

modules/cabana/testdata/deferred/models/member/fields.yaml

@@ -0,0 +1,5 @@
+fields:
+    email:
+        label: Email
+        type: text
+        required: true

modules/cabana/testdata/deferred/models/member/pivot_fields.yaml

@@ -0,0 +1,4 @@
+fields:
+    pivot[note]:
+        label: Note
+        type: text

modules/cabana/testdata/deferred/models/part/fields.yaml

@@ -0,0 +1,19 @@
+fields:
+    label:
+        label: Label
+        type: text
+        required: true
+    due_on:
+        label: Due on
+        type: datepicker
+        mode: date
+        minDate: 2020-01-01
+    images:
+        label: Images
+        type: fileupload
+        mode: image
+        useCaption: true
+    sheet:
+        label: Sheet
+        type: fileupload
+        fileTypes: [txt, pdf]