Add Deck workflow automation Nextcloud app

Ports the standalone due-date cron script into a proper Nextcloud 34
app with a personal-settings UI, per-user workflow configuration
(source/target stack, assigned-user and label filters, email
notification), a TimedJob background runner, and Gitea CI pipelines.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/api.js

@@ -0,0 +1,45 @@
+import axios from '@nextcloud/axios'
+import { generateOcsUrl } from '@nextcloud/router'
+
+function ocsUrl(path) {
+	return generateOcsUrl(`apps/workflow_deck_automation/api/v1${path}`)
+}
+
+export async function fetchWorkflows() {
+	const { data } = await axios.get(ocsUrl('/workflows'))
+	return data.ocs.data
+}
+
+export async function createWorkflow(payload) {
+	const { data } = await axios.post(ocsUrl('/workflows'), payload)
+	return data.ocs.data
+}
+
+export async function updateWorkflow(id, payload) {
+	const { data } = await axios.put(ocsUrl(`/workflows/${id}`), payload)
+	return data.ocs.data
+}
+
+export async function deleteWorkflow(id) {
+	await axios.delete(ocsUrl(`/workflows/${id}`))
+}
+
+export async function fetchBoards() {
+	const { data } = await axios.get(ocsUrl('/boards'))
+	return data.ocs.data
+}
+
+export async function fetchStacks(boardId) {
+	const { data } = await axios.get(ocsUrl(`/boards/${boardId}/stacks`))
+	return data.ocs.data
+}
+
+export async function fetchLabels(boardId) {
+	const { data } = await axios.get(ocsUrl(`/boards/${boardId}/labels`))
+	return data.ocs.data
+}
+
+export async function fetchParticipants(boardId) {
+	const { data } = await axios.get(ocsUrl(`/boards/${boardId}/participants`))
+	return data.ocs.data
+}