test(10.1-04): cover the Phase 10.1 extension point Go code

- acme fixture plugin under modules/cabana/testdata/extension (gadgets
  controller, header and form partials, lookup widget, JS and CSS)
- TestPhase101FormExtensionSchema, TestPhase101PartialSchema and
  TestPhase101Toolbar: every widget, partial and toolbar boot rule
- TestPhase101PartialSanitizer: tag, attribute and URL allowlist, escaping,
  per-request trans, size/node/depth caps and the view-model guard
- TestPhase101Assets: exact-key asset hits, revalidation, SPA fall-through,
  boot path checks and ?v= schema URLs
- TestPhase101Actions (PostgreSQL): scoping, fill filter, strict body,
  action permission, error mapping, CSRF header, toolbar and partial routes
- TestPhase101BoardwalkExports: ContentType and SetSecurityHeaders

modules/cabana/testdata/extension/assets/css/gadgets.css

@@ -0,0 +1,4 @@
+acme-demo-lookup button {
+  font: inherit;
+  color: var(--c-text);
+}

modules/cabana/testdata/extension/assets/js/lookup.js

@@ -0,0 +1,18 @@
+// A plain custom element: one light-DOM button that asks the admin SPA to
+// run the field's action. It makes no request and reads no cookie or
+// storage; the SPA owns HTTP.
+class AcmeDemoLookup extends HTMLElement {
+  connectedCallback() {
+    if (this.firstChild) return
+    const button = document.createElement('button')
+    button.type = 'button'
+    button.textContent = this.getAttribute('label') || ''
+    button.addEventListener('click', () => {
+      this.dispatchEvent(new CustomEvent('summer-action', { bubbles: true, composed: true }))
+    })
+    this.append(button)
+  }
+}
+if (!customElements.get('acme-demo-lookup')) {
+  customElements.define('acme-demo-lookup', AcmeDemoLookup)
+}

modules/cabana/testdata/extension/controllers/gadgets/_stats.htm

@@ -0,0 +1,5 @@
+<dl class="summer-stats">
+{{- range .Data.Items -}}
+<div class="summer-stat"><dt class="summer-stat__label">{{ trans .Label }}</dt><dd class="summer-stat__value">{{ .Count }}</dd></div>
+{{- end -}}
+</dl>

modules/cabana/testdata/extension/controllers/gadgets/_summary.htm

@@ -0,0 +1 @@
+<section class="summer-partial" aria-label="{{ trans "acme.demo::lang.gadgets.summary" }}"><p>{{ .Data.Name }}</p></section>

modules/cabana/testdata/extension/controllers/gadgets/config_form.yaml

@@ -0,0 +1,10 @@
+name: acme.demo::lang.gadgets.form
+form: ~/plugins/acme/demo/models/gadget/fields.yaml
+modelClass: Gadget
+defaultRedirect: acme/demo/gadgets
+create:
+    redirect: acme/demo/gadgets/update/:id
+    redirectClose: acme/demo/gadgets
+update:
+    redirect: acme/demo/gadgets
+    redirectClose: acme/demo/gadgets

modules/cabana/testdata/extension/controllers/gadgets/config_list.yaml

@@ -0,0 +1,11 @@
+list: ~/plugins/acme/demo/models/gadget/columns.yaml
+modelClass: Gadget
+title: acme.demo::lang.gadgets.title
+recordUrl: acme/demo/gadgets/update/:id
+recordsPerPage: 20
+showCheckboxes: true
+headerPartial: stats
+toolbar:
+    buttons: [create, delete, recount]
+    search:
+        prompt: backend::lang.list.search_prompt

modules/cabana/testdata/extension/lang/en/lang.yaml

@@ -0,0 +1,12 @@
+gadgets:
+  title: Gadgets
+  form: Gadget
+  name: Name
+  active: Active
+  group: Group
+  lookup: Lookup
+  summary: Summary
+  total: All gadgets
+  recount: Recount
+  recounted: Gadgets were recounted.
+  looked_up: Name and Active were filled in.

modules/cabana/testdata/extension/lang/pl/lang.yaml

@@ -0,0 +1,12 @@
+gadgets:
+  title: Gadżety
+  form: Gadżet
+  name: Nazwa
+  active: Aktywny
+  group: Grupa
+  lookup: Wyszukaj
+  summary: Podsumowanie
+  total: Wszystkie gadżety
+  recount: Przelicz
+  recounted: Gadżety zostały przeliczone.
+  looked_up: Uzupełniono Nazwę i Aktywny.

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

@@ -0,0 +1,7 @@
+columns:
+    name:
+        label: acme.demo::lang.gadgets.name
+        searchable: true
+    active:
+        label: acme.demo::lang.gadgets.active
+        type: switch

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

@@ -0,0 +1,23 @@
+fields:
+    name:
+        label: acme.demo::lang.gadgets.name
+        type: text
+        span: left
+    active:
+        label: acme.demo::lang.gadgets.active
+        type: switch
+        span: right
+    group:
+        label: acme.demo::lang.gadgets.group
+        type: relation
+        nameFrom: title
+    lookup:
+        label: acme.demo::lang.gadgets.lookup
+        type: widget
+        widget: acme-demo-lookup
+        action: lookup
+        fill: [name, active]
+    summary:
+        label: acme.demo::lang.gadgets.summary
+        type: partial
+        path: summary