feat: Implementar PWA, Analytics, Reportes PDF y mejoras OCR

FASE 1 - PWA y Frontend:
- Crear templates/base.html, dashboard.html, analytics.html, executive.html
- Crear static/css/main.css con diseño responsivo
- Agregar static/js/app.js, pwa.js, camera.js, charts.js
- Implementar manifest.json y service-worker.js para PWA
- Soporte para captura de tickets desde cámara móvil

FASE 2 - Analytics:
- Crear módulo analytics/ con predictions.py, trends.py, comparisons.py
- Implementar predicción básica con promedio móvil + tendencia lineal
- Agregar endpoints /api/analytics/trends, predictions, comparisons
- Integrar Chart.js para gráficas interactivas

FASE 3 - Reportes PDF:
- Crear módulo reports/ con pdf_generator.py
- Implementar SalesReportPDF con generar_reporte_diario y ejecutivo
- Agregar comando /reporte [diario|semanal|ejecutivo]
- Agregar endpoints /api/reports/generate y /api/reports/download

FASE 4 - Mejoras OCR:
- Crear módulo ocr/ con processor.py, preprocessor.py, patterns.py
- Implementar AmountDetector con patrones múltiples de montos
- Agregar preprocesador adaptativo con pipelines para diferentes condiciones
- Soporte para corrección de rotación (deskew) y threshold Otsu

Dependencias agregadas:
- reportlab, matplotlib (PDF)
- scipy, pandas (analytics)
- imutils, deskew, cachetools (OCR)

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

sales-bot/static/manifest.json

@@ -0,0 +1,83 @@
+{
+    "name": "Sales Bot - Sistema de Ventas",
+    "short_name": "Sales Bot",
+    "description": "Sistema de seguimiento y automatizacion de ventas",
+    "start_url": "/dashboard",
+    "display": "standalone",
+    "orientation": "portrait-primary",
+    "background_color": "#1a1a2e",
+    "theme_color": "#00d4ff",
+    "scope": "/",
+    "lang": "es-MX",
+    "categories": ["business", "productivity"],
+    "icons": [
+        {
+            "src": "/static/icons/icon-72x72.png",
+            "sizes": "72x72",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-96x96.png",
+            "sizes": "96x96",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-128x128.png",
+            "sizes": "128x128",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-144x144.png",
+            "sizes": "144x144",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-152x152.png",
+            "sizes": "152x152",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-192x192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-384x384.png",
+            "sizes": "384x384",
+            "type": "image/png",
+            "purpose": "any maskable"
+        },
+        {
+            "src": "/static/icons/icon-512x512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "any maskable"
+        }
+    ],
+    "screenshots": [],
+    "shortcuts": [
+        {
+            "name": "Dashboard",
+            "url": "/dashboard",
+            "description": "Ver dashboard principal"
+        },
+        {
+            "name": "Analytics",
+            "url": "/dashboard/analytics",
+            "description": "Ver analytics y graficas"
+        },
+        {
+            "name": "Ejecutivo",
+            "url": "/dashboard/executive",
+            "description": "Ver dashboard ejecutivo"
+        }
+    ],
+    "related_applications": [],
+    "prefer_related_applications": false
+}