feat: add example dashboard widget + splitChunks bundling pattern

[rubenvdlinde]

Wires the ConductionNL bundling pattern from ADR-004 into the template so every new app cloned from this repo:

1. Gets a working Nextcloud Dashboard widget out of the box (the ExampleWidget)
2. Inherits the optimization.splitChunks config that prevents Vue + @nextcloud/vue + pinia from being inlined into every entry-point
3. Has the appName / appVersion DefinePlugin lines already in place

Triggered by the recent mydash page-load investigation: every Conduction app with dashboard widgets had grown a duplicated-framework problem (228 MB of widget JS attached to /apps/mydash/ across opencatalogi + pipelinq + procest + docudesk + mydash). The fixes landed in those repos; this PR captures the pattern in the template so future apps don't repeat it.

What changed

File	Why
webpack.config.js	Adds optimization.splitChunks with stable-filename -shared-vendor + -shared-nc-vue chunks; adds exampleWidget entry-point
lib/Dashboard/ExampleWidget.php	Minimal IWidget. load() attaches the two shared chunks before the per-widget bundle (order: vendor → nc-vue → widget)
src/exampleWidget.js	Webpack entry that registers via OCA.Dashboard.register. Hard-coded id matches Widget::getId()
src/views/widgets/ExampleWidget.vue	Minimal NcDashboardWidget with axios fetch + graceful empty state
lib/AppInfo/Application.php	$context->registerDashboardWidget(ExampleWidget::class)
README.md	"Adding a dashboard widget" how-to + directory-tree update

How an app cloning this template removes the widget

Apps without dashboard widgets delete:

• lib/Dashboard/ + src/exampleWidget.js + src/views/widgets/
• the registerDashboardWidget(...) line in Application.php
• the exampleWidget entry in webpack.config.js

The splitChunks block is harmless with only main + adminSettings entries (produces small shared chunks that two entries reuse) and starts paying off the moment a widget is added.

Test plan

• npm install && npm run build succeeds
• js/ contains app-template-shared-vendor.js, app-template-shared-nc-vue.js, app-template-exampleWidget.js
• App enables in a Nextcloud install
• Open /apps/dashboard/ (or mydash), confirm "Example widget" appears in the widget picker

[github-actions]

Quality Report — ConductionNL/nextcloud-app-template @ 1752fc1

Check	PHP	Vue	Security	License	Tests
lint	✅
phpcs	✅
phpmd	✅
psalm	✅
phpstan	✅
phpmetrics	✅
eslint		✅
stylelint		✅
composer			✅	✅ 100/100
npm			✅	✅ 215/215
PHPUnit					✅
Newman					✅
Playwright					⏭️

Coverage: 0% (0/3 statements)

---

Quality workflow — 2026-05-05 07:02 UTC

Download the full PDF report from the workflow artifacts.

[rubenvdlinde]

Validated locally:

exampleWidget (3.42 MiB)
    app-template-shared-nc-vue.js  2.88 MB
    app-template-shared-vendor.js  0.34 MB
    app-template-exampleWidget.js  0.19 MB

Per-widget bundle is 190 KB (just widget code). Shared chunks load once across the page. Same pattern as pipelinq/procest/docudesk and matches ADR-004.