feat: Add major features - Mejoras 5-10

- Mejora 5: Órdenes de Compra integration in obra detail
- Mejora 6: Portal de Cliente with JWT auth for clients
- Mejora 7: Diagrama de Gantt for project visualization
- Mejora 8: Push Notifications with service worker
- Mejora 9: Activity Log system with templates
- Mejora 10: PWA support with offline capabilities

New features include:
- Fotos gallery with upload/delete
- Bitácora de obra with daily logs
- PDF export for reports, gastos, presupuestos
- Control de asistencia for employees
- Client portal with granular permissions
- Gantt chart with task visualization
- Push notification system
- Activity timeline component
- PWA manifest, icons, and install prompt

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

public/manifest.json

@@ -0,0 +1,103 @@
+{
+  "name": "Mexus - Gestión de Obras",
+  "short_name": "Mexus",
+  "description": "Sistema de gestión de obras de construcción",
+  "start_url": "/dashboard",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#2563eb",
+  "orientation": "portrait-primary",
+  "scope": "/",
+  "icons": [
+    {
+      "src": "/icons/icon-72x72.png",
+      "sizes": "72x72",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-96x96.png",
+      "sizes": "96x96",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-128x128.png",
+      "sizes": "128x128",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-144x144.png",
+      "sizes": "144x144",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-152x152.png",
+      "sizes": "152x152",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-384x384.png",
+      "sizes": "384x384",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "maskable any"
+    }
+  ],
+  "categories": ["business", "productivity"],
+  "screenshots": [
+    {
+      "src": "/screenshots/dashboard.png",
+      "sizes": "1280x720",
+      "type": "image/png",
+      "form_factor": "wide",
+      "label": "Dashboard principal"
+    },
+    {
+      "src": "/screenshots/obras.png",
+      "sizes": "1280x720",
+      "type": "image/png",
+      "form_factor": "wide",
+      "label": "Gestión de obras"
+    }
+  ],
+  "shortcuts": [
+    {
+      "name": "Dashboard",
+      "short_name": "Dashboard",
+      "description": "Ver dashboard principal",
+      "url": "/dashboard",
+      "icons": [{ "src": "/icons/icon-96x96.png", "sizes": "96x96" }]
+    },
+    {
+      "name": "Obras",
+      "short_name": "Obras",
+      "description": "Ver lista de obras",
+      "url": "/obras",
+      "icons": [{ "src": "/icons/icon-96x96.png", "sizes": "96x96" }]
+    },
+    {
+      "name": "Nueva Obra",
+      "short_name": "Nueva",
+      "description": "Crear nueva obra",
+      "url": "/obras/nueva",
+      "icons": [{ "src": "/icons/icon-96x96.png", "sizes": "96x96" }]
+    }
+  ],
+  "related_applications": [],
+  "prefer_related_applications": false
+}