feat(17-02): richeditor field on TipTap with the untouched rule

- RichEditorField: Reka toolbar, link popover with the http/https/mailto/tel
  and relative URL policy, Edit HTML view, lossy note, skeleton while the
  lazily imported TipTap chunk loads, HTML view fallback when it fails
- untouched values are submitted byte-identical; after an edit the value is
  the editor HTML (empty paragraph -> ""); a value from outside (the save's
  sanitized answer) reloads the editor
- read-only renders through a client display allowlist, never as stored
- TipTap 3.31.4 (core, pm, starter-kit) pinned exact after the package check
- richeditor.* phrase keys (en, pl), smoke specs, forms docs

admin/tests/fixtures/companions.form-schema.json

@@ -0,0 +1,27 @@
+{
+  "data": {
+    "name": "Link",
+    "modelClass": "Link",
+    "fields": [
+      { "name": "title", "type": "text", "label": "Title", "span": "left" },
+      { "name": "description", "type": "richeditor", "label": "Description", "comment": "Shown under the title." }
+    ],
+    "messages": {
+      "create": { "other": "New link" },
+      "update": { "other": "Edit link" },
+      "saved": { "other": "Saved" },
+      "deleteConfirm": { "other": "Delete this record?" },
+      "deleted": { "other": "Record deleted" },
+      "preview": { "other": "Link details" },
+      "edit": { "other": "Edit link" }
+    },
+    "redirects": {
+      "default": "acme/companions/links",
+      "create": { "redirect": "acme/companions/links/:id", "redirectClose": "acme/companions/links" },
+      "update": { "redirect": "acme/companions/links", "redirectClose": "acme/companions/links" }
+    },
+    "meta": { "locale": "en" },
+    "assets": { "scripts": [], "styles": [] }
+  },
+  "meta": { "locale": "en" }
+}

admin/tests/fixtures/lang.json

@@ -609,6 +609,81 @@
     "backend::lang.relation.unlink": {
       "other": "Odłącz"
     },
+    "backend::lang.richeditor.bold": {
+      "other": "Pogrubienie"
+    },
+    "backend::lang.richeditor.bullet_list": {
+      "other": "Lista punktowana"
+    },
+    "backend::lang.richeditor.heading": {
+      "other": "Nagłówek"
+    },
+    "backend::lang.richeditor.italic": {
+      "other": "Kursywa"
+    },
+    "backend::lang.richeditor.link": {
+      "other": "Link"
+    },
+    "backend::lang.richeditor.link_apply": {
+      "other": "Zastosuj link"
+    },
+    "backend::lang.richeditor.link_invalid": {
+      "other": "Link musi używać http, https, mailto, tel albo adresu względnego."
+    },
+    "backend::lang.richeditor.link_url": {
+      "other": "Adres linku"
+    },
+    "backend::lang.richeditor.load_failed": {
+      "other": "Nie udało się wczytać edytora. Możesz edytować HTML bezpośrednio."
+    },
+    "backend::lang.richeditor.lossy_note": {
+      "other": "Części formatowania tego tekstu nie da się pokazać w edytorze. Użyj „Edytuj HTML”, aby zmienić tekst bez jej utraty."
+    },
+    "backend::lang.richeditor.markup_changed": {
+      "other": "Filtr HTML zmienił część znaczników."
+    },
+    "backend::lang.richeditor.ordered_list": {
+      "other": "Lista numerowana"
+    },
+    "backend::lang.richeditor.quote": {
+      "other": "Cytat"
+    },
+    "backend::lang.richeditor.redo": {
+      "other": "Ponów"
+    },
+    "backend::lang.richeditor.removed_attributes": {
+      "one": "Usunięto :count atrybut: :names",
+      "few": "Usunięto :count atrybuty: :names",
+      "many": "Usunięto :count atrybutów: :names",
+      "other": "Usunięto :count atrybutu: :names"
+    },
+    "backend::lang.richeditor.removed_comments": {
+      "one": "Usunięto :count komentarz HTML",
+      "few": "Usunięto :count komentarze HTML",
+      "many": "Usunięto :count komentarzy HTML",
+      "other": "Usunięto :count komentarza HTML"
+    },
+    "backend::lang.richeditor.removed_elements": {
+      "one": "Usunięto :count element: :names",
+      "few": "Usunięto :count elementy: :names",
+      "many": "Usunięto :count elementów: :names",
+      "other": "Usunięto :count elementu: :names"
+    },
+    "backend::lang.richeditor.source": {
+      "other": "Edytuj HTML"
+    },
+    "backend::lang.richeditor.toolbar": {
+      "other": "Formatowanie"
+    },
+    "backend::lang.richeditor.underline": {
+      "other": "Podkreślenie"
+    },
+    "backend::lang.richeditor.undo": {
+      "other": "Cofnij"
+    },
+    "backend::lang.richeditor.unlink": {
+      "other": "Usuń link"
+    },
     "backend::lang.settings.back": {
       "other": "Wróć do ustawień"
     },

admin/tests/fixtures/typed.ts

@@ -7,6 +7,7 @@ import type { components } from '../../src/api/schema'
 import langJson from './lang.json'
 import navigationJson from './navigation.json'
 import settingsJson from './settings.json'
+import companionsFormSchemaJson from './companions.form-schema.json'
 import extensionFormSchemaJson from './extension.form-schema.json'
 import extensionListSchemaJson from './extension.list-schema.json'
 import extensionPartialJson from './extension.partial.json'
@@ -46,6 +47,8 @@ export const deferredRelationSchemaFixture: {
 } = deferredRelationSchemaJson
 /** A protected file list: a captioned image, a pending image and a PDF (Phase 12.2). */
 export const deferredFilesFixture: S['cabana.Envelope-array_cabana_FileItem'] = deferredFilesJson
+/** A link form with the Phase 17 field types: richeditor, repeater and a dependent dropdown. */
+export const companionsFormSchemaFixture: S['cabana.Envelope-cabana_FormView'] = companionsFormSchemaJson
 /** A form with a plugin widget and its controller script (Phase 10.1). */
 export const extensionFormSchemaFixture: S['cabana.Envelope-cabana_FormView'] = extensionFormSchemaJson
 /** A list with a header partial and a controller stylesheet (Phase 10.1). */