feat: tasks app, security hardening, mobile fixes, iOS app shell

- Custom SQLite task manager replacing TickTick wrapper
- 73 tasks migrated from TickTick across 15 projects
- RRULE recurrence engine with lazy materialization
- Dashboard tasks widget (desktop sidebar + mobile card)
- Tasks page with project tabs, add/edit/complete/delete
- Security: locked ports to localhost, removed old containers
- Gitea Actions runner configured and all 3 CI jobs passing
- Fixed mobile overflow on dashboard cards
- iOS Capacitor app shell (Second Brain)
- Frontend/backend guide docs for adding new services
- TickTick Google Calendar sync re-authorized

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend-v2/src/lib/components/layout/MobileTabBar.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 	import { page } from '$app/state';
-	import { LayoutDashboard, DollarSign, Package, Activity, MoreVertical, MapPin, BookOpen, Library, Settings } from '@lucide/svelte';
+	import { LayoutDashboard, DollarSign, Package, Activity, MoreVertical, MapPin, BookOpen, Library, Settings, CheckSquare } from '@lucide/svelte';
 
 	interface Props {
 		visibleApps?: string[];
@@ -60,6 +60,12 @@
 	<div class="more-sheet-overlay open" onclick={(e) => { if (e.target === e.currentTarget) closeMore(); }} onkeydown={() => {}}>
 		<div class="more-sheet">
 			<div class="more-sheet-handle"></div>
+			{#if showApp('tasks')}
+				<a href="/tasks" class="more-sheet-item" onclick={closeMore}>
+					<CheckSquare size={20} />
+					Tasks
+				</a>
+			{/if}
 			{#if showApp('trips')}
 				<a href="/trips" class="more-sheet-item" onclick={closeMore}>
 					<MapPin size={20} />