FASE 4-5-6: Infraestructura, CRM, Service Orders, Notificaciones, Ahorro, Logistica, API Publica

FASE 4:
- Redis cache de stock con fallback graceful
- Multi-moneda (MXN/USD) con contabilidad en MXN
- Proveedores y ordenes de compra completo
- Meilisearch 1.5M+ partes indexadas
- Metabase KPIs con dashboard auto-generado

FASE 5:
- CRM mejorado: activities, tags, loyalty program, analytics
- Imagenes de partes: upload, resize, thumbnails WebP
- Ordenes de servicio Kanban: received->diagnosis->repair->ready->delivered
- Garantias/RMA, alertas de reorden, multi-sucursal
- Stubs BNPL (APLAZO) y ERP Sync (Aspel/Contpaqi)

FASE 6:
- Notificaciones automaticas: push/WhatsApp/email/in-app
- Reportes de ahorro vs retail_price
- Logistica + tracking: DHL, FedEx, Estafeta, 99min, Uber
- API Publica: API keys, rate limiting, catalog search

Migraciones: v1.9-v3.0
Tests: 93/93 pasando
Backup: nexus_backup_20260427_045859.tar.gz

pos/services/meili_search.py

@@ -0,0 +1,159 @@
+"""Meilisearch integration for sub-100ms catalog search.
+
+Provides a thin wrapper over the meilisearch Python client with:
+- Automatic index creation and settings configuration
+- Bulk indexing from PostgreSQL
+- Search with graceful fallback to PostgreSQL tsvector
+- Incremental add/update/delete for real-time sync
+
+Environment:
+    MEILI_URL      — Meilisearch server URL (default: http://localhost:7700)
+    MEILI_API_KEY  — Master key (default: nexus-master-key-change-me)
+"""
+
+import os
+import meilisearch
+from meilisearch.errors import MeilisearchApiError
+
+MEILI_URL = os.environ.get('MEILI_URL', 'http://localhost:7700')
+MEILI_API_KEY = os.environ.get('MEILI_API_KEY', 'nexus-master-key-change-me')
+INDEX_NAME = 'nexus_parts'
+
+# Searchable attributes and ranking
+INDEX_SETTINGS = {
+    'searchableAttributes': [
+        'name_es',
+        'name_part',
+        'oem_part_number',
+        'description',
+        'description_es',
+    ],
+    'rankingRules': [
+        'words',
+        'typo',
+        'proximity',
+        'attribute',
+        'sort',
+        'exactness',
+    ],
+    'filterableAttributes': ['group_id'],
+    'typoTolerance': {'enabled': True, 'minWordSizeForTypos': {'oneTypo': 4, 'twoTypos': 8}},
+}
+
+_client = None
+_client_url = None
+
+
+def get_client():
+    """Get or create Meilisearch client (lazy singleton, URL-aware)."""
+    global _client, _client_url
+    current_url = os.environ.get('MEILI_URL', 'http://localhost:7700')
+    if _client is None or _client_url != current_url:
+        _client = meilisearch.Client(current_url, MEILI_API_KEY)
+        _client_url = current_url
+    return _client
+
+
+def reset_client():
+    """Force client recreation on next use (useful for tests)."""
+    global _client, _client_url
+    _client = None
+    _client_url = None
+
+
+def health_check():
+    """Return True if Meilisearch is reachable."""
+    try:
+        return get_client().health().get('status') == 'available'
+    except Exception:
+        return False
+
+
+def ensure_index():
+    """Create index if it doesn't exist and configure settings."""
+    client = get_client()
+    try:
+        client.get_index(INDEX_NAME)
+    except MeilisearchApiError as e:
+        if e.code == 'index_not_found':
+            client.create_index(uid=INDEX_NAME, options={'primaryKey': 'id_part'})
+        else:
+            raise
+
+    index = client.index(INDEX_NAME)
+    index.update_settings(INDEX_SETTINGS)
+    return index
+
+
+def index_parts_bulk(parts_iter, batch_size=1000):
+    """Index a large number of parts from an iterable.
+
+    Args:
+        parts_iter: iterable of dicts with keys:
+            id_part, oem_part_number, name_part, name_es,
+            description, description_es, image_url, group_id
+        batch_size: documents per batch upload
+    """
+    index = ensure_index()
+    batch = []
+    total = 0
+    for part in parts_iter:
+        batch.append(part)
+        if len(batch) >= batch_size:
+            index.add_documents(batch)
+            total += len(batch)
+            batch = []
+    if batch:
+        index.add_documents(batch)
+        total += len(batch)
+    return total
+
+
+def search_parts(query, limit=50, offset=0):
+    """Search parts via Meilisearch.
+
+    Returns:
+        dict: Meilisearch response with 'hits', 'offset', 'limit', 'totalHits'
+        or None on error.
+    """
+    try:
+        index = get_client().index(INDEX_NAME)
+        return index.search(query, {'limit': limit, 'offset': offset})
+    except Exception as e:
+        print(f"[meili_search] Search error: {e}")
+        return None
+
+
+def add_part(part_doc):
+    """Add or update a single part document."""
+    try:
+        get_client().index(INDEX_NAME).add_documents([part_doc])
+        return True
+    except Exception as e:
+        print(f"[meili_search] Add error: {e}")
+        return False
+
+
+def update_part(part_doc):
+    """Update a single part document (same as add)."""
+    return add_part(part_doc)
+
+
+def delete_part(part_id):
+    """Remove a part from the index."""
+    try:
+        get_client().index(INDEX_NAME).delete_document(part_id)
+        return True
+    except Exception as e:
+        print(f"[meili_search] Delete error: {e}")
+        return False
+
+
+def clear_index():
+    """Delete all documents from the index."""
+    try:
+        get_client().index(INDEX_NAME).delete_all_documents()
+        return True
+    except Exception as e:
+        print(f"[meili_search] Clear error: {e}")
+        return False