Initial commit: note-taking/task-tracking app with LLM integration scaffold

Vue 3 + TypeScript frontend with Pinia stores, markdown rendering (marked + DOMPurify),
wikilink/tag linkification, and autocomplete. Quart async backend with SQLAlchemy 2.0,
PostgreSQL ARRAY columns, task-note companion linking, backlinks, and note-to-task
conversion. Docker Compose setup with PostgreSQL 16 and Ollama.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/App.vue

@@ -0,0 +1,13 @@
+<script setup lang="ts">
+import AppHeader from "@/components/AppHeader.vue";
+import ToastNotification from "@/components/ToastNotification.vue";
+import { useTheme } from "@/composables/useTheme";
+
+useTheme();
+</script>
+
+<template>
+  <AppHeader />
+  <router-view />
+  <ToastNotification />
+</template>