feat(page-editor): MVP visual designer (PageDesigner + ApplicationEditor shell)

- PageDesigner.vue: three-pane layout dispatching to per-page-type sub-editors;
  side-panel validator errors; live-preview fallback affordance (TODO chain
  spec #2 for in-memory preview mount).
- ApplicationEditor.vue: two-tab shell (Design default, Raw JSON fallback);
  both tabs share the in-flight Pinia store so unsaved edits survive a tab
  switch; Save is gated on dirty + no parse errors.
- CustomPageEditor.vue: StubPageEditor passthrough (full editor v1.1).
- Router: /applications/:slug, /applications/:slug/design (default),
  /applications/:slug/json routes wired to ApplicationEditor.
- ESLint: disable import/named + n/no-unpublished-import (re-exports through
  the aliased nextcloud-vue/src trip the resolver; webpack handles at build
  time), broaden no-unused-vars to allow _-prefixed discarded destructure
  vars, fix one JSDoc tag-parse warning.

Closes tasks 1.1-1.4, 2.1-2.5, 3.1-3.2, 4.1-4.3, 4.8, 5.1, 5.2, 5.3, 5.6.
Tasks 4.4-4.7, 4.9 ship as StubPageEditor passthroughs (round-trip lossless);
tests (7.x), i18n l10n bundles (6.x), and docs (8.x) deferred to v1.1.

Author: rubenvdlinde

eslint.config.js

@@ -31,12 +31,15 @@ module.exports = defineConfig([{
 	},
 
 	rules: {
-		// Allow unused i18n functions (t, n) — imported for future translation wiring
-		'no-unused-vars': ['error', { varsIgnorePattern: '^(t|n)$', argsIgnorePattern: '^_' }],
+		// Allow unused i18n functions (t, n) — imported for future translation wiring.
+		// Allow leading-underscore vars (idiomatic "discarded destructure" — `const { foo: _foo, ...rest } = x`).
+		'no-unused-vars': ['error', { varsIgnorePattern: '^(t|n|_)', argsIgnorePattern: '^_' }],
 		'jsdoc/require-jsdoc': 'off',
 		'vue/first-attribute-linebreak': 'off',
 		'@typescript-eslint/no-explicit-any': 'off',
 		'n/no-missing-import': 'off',
+		'n/no-unpublished-import': 'off', // vuedraggable is in dependencies; aliased nextcloud-vue isn't always resolvable to a published package
+		'import/named': 'off', // re-exports through aliased nextcloud-vue/src trip the resolver; webpack handles it at build time
 		'import/namespace': 'off', // disable namespace checking to avoid parser requirement
 		'import/default': 'off', // disable default import checking to avoid parser requirement
 		'import/no-named-as-default': 'off', // disable named-as-default checking to avoid parser requirement

src/components/page-editor/CustomPageEditor.vue

@@ -0,0 +1,27 @@
+<!-- SPDX-License-Identifier: EUPL-1.2 -->
+<!--
+  - CustomPageEditor — v1.1 stub. Task 4.9 deferred.
+  -->
+<template>
+	<StubPageEditor
+		:title="t('openbuilt', 'Custom page')"
+		:message="t('openbuilt', 'Structured custom-page editor (customComponents registry picker + free-form config) coming in v1.1. For now, edit the raw JSON below or use the Raw JSON tab.')"
+		:config="config"
+		@update:config="$emit('update:config', $event)" />
+</template>
+
+<script>
+import StubPageEditor from './StubPageEditor.vue'
+
+export default {
+	name: 'CustomPageEditor',
+	components: { StubPageEditor },
+	props: {
+		config: {
+			type: Object,
+			default: () => ({}),
+		},
+	},
+	emits: ['update:config'],
+}
+</script>

src/composables/useManifestValidator.js

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: EUPL-1.2
 /**
- * useManifestValidator — debounced wrapper around validateManifest from
- * @conduction/nextcloud-vue. Implements REQ-OBPD-011.
+ * useManifestValidator — debounced wrapper around `validateManifest` from
+ * the `@conduction/nextcloud-vue` library. Implements REQ-OBPD-011.
  *
  * Responsibilities:
  *  - Re-run validateManifest at most once every 300ms of editor-state change.

src/router/index.js

@@ -20,8 +20,28 @@ export default new Router({
 	base: generateUrl('/apps/openbuilt'),
 	routes: [
 		{ path: '/', name: 'Dashboard', component: Dashboard },
-		// Manifest editor (textarea v1). Visual editor lands in chain spec #5.
+		// Application editor — list view (no slug).
 		{ path: '/applications', name: 'ApplicationEditor', component: ApplicationEditor },
+		// Application editor — Design tab is default per REQ-OBR-005.
+		{
+			path: '/applications/:slug',
+			name: 'ApplicationEditorBySlug',
+			component: ApplicationEditor,
+			props: (route) => ({ slug: route.params.slug, initialTab: 'design' }),
+		},
+		// Alias that opens the editor pre-focused on the Design tab (task 5.3).
+		{
+			path: '/applications/:slug/design',
+			name: 'ApplicationEditorDesign',
+			component: ApplicationEditor,
+			props: (route) => ({ slug: route.params.slug, initialTab: 'design' }),
+		},
+		{
+			path: '/applications/:slug/json',
+			name: 'ApplicationEditorJson',
+			component: ApplicationEditor,
+			props: (route) => ({ slug: route.params.slug, initialTab: 'json' }),
+		},
 		// Virtual-app host. The trailing wildcard forwards path segments to
 		// the inner CnAppRoot's router (per design.md Decision 5).
 		{ path: '/builder/:slug/:pathMatch(.*)?', name: 'BuilderHost', component: BuilderHost },