feat(catalog): supplier catalog cleanup, fuzzy matching, and navigation fixes

- Cleaned 137+ fake engine-displacement models from supplier imports
  (v3/v4 scripts: Chevrolet, Ford, Chrysler, Dodge, Jeep, Nissan, etc.)
- Removed 1,251+ corrupted models (INT. prefixes, year-suffix, torque specs,
  empty names, trailing-year variants)
- Migrated supplier tables to master DB (supplier_catalog,
  supplier_catalog_compat, supplier_catalog_interchange)
- Fixed _get_mye_ids_with_parts() to query supplier_catalog_compat from
  master DB so supplier-only vehicles appear for all tenants
- Added fuzzy model matcher with parenthesis stripping, noise suffix removal,
  compact matching, prefix/substring fallback, model aliases, and ±3 year
  proximity
- Matched compat rows: KEEP GREEN +14,152, KNADIAN +3,021, VAZLO +127,500,
  LUK +477, RAYBESTOS +1,743
- Added KNADIAN catalog importer with year-range expansion and future-year
  filtering
- Added VAZLO catalog importer with position parsing and SKU-in-model cleanup
- Added Keep Green, LUK, Yokomitsu, Raybestos catalog importers
- Cache clearing after cleanups (_classify_cache_*, nexus:mye_ids:*,
  nexus:brand_mye_counts:*)

Final match rates:
- KEEP GREEN: 90.3%
- VAZLO: 93.6%
- YOKOMITSU: 100.0%
- KNADIAN: 57.4%
- LUK: 51.0%
- RAYBESTOS: 55.9%

pos/services/webhook_service.py

@@ -0,0 +1,65 @@
+"""Webhook dispatch service for dropshipping and external integrations.
+
+Sends POST requests to configured target URLs with retry logic.
+Can be called synchronously or enqueued via Celery.
+"""
+
+import json
+import logging
+import requests
+import threading
+from typing import Optional
+
+logger = logging.getLogger(__name__)
+
+
+def _send_post(url: str, payload: dict, headers: Optional[dict] = None, timeout: int = 10):
+    """Send a POST request and return (success, status_code, response_text)."""
+    default_headers = {"Content-Type": "application/json"}
+    if headers:
+        default_headers.update(headers)
+    try:
+        resp = requests.post(url, json=payload, headers=default_headers, timeout=timeout)
+        success = 200 <= resp.status_code < 300
+        if not success:
+            logger.warning("Webhook %s returned %s: %s", url, resp.status_code, resp.text[:200])
+        return success, resp.status_code, resp.text
+    except requests.exceptions.Timeout:
+        logger.warning("Webhook %s timed out after %ss", url, timeout)
+        return False, 0, "timeout"
+    except Exception as e:
+        logger.warning("Webhook %s failed: %s", url, e)
+        return False, 0, str(e)
+
+
+def dispatch_webhook_sync(target_url: str, event_type: str, payload: dict, secret: Optional[str] = None):
+    """Send webhook synchronously (use inside Celery tasks for async)."""
+    full_payload = {
+        "event": event_type,
+        "data": payload,
+    }
+    headers = {}
+    if secret:
+        headers["X-Webhook-Secret"] = secret
+    success, status, body = _send_post(target_url, full_payload, headers=headers)
+    return {"success": success, "status": status, "body": body[:500]}
+
+
+def dispatch_webhooks_bulk(target_urls: list[str], event_type: str, payload: dict, secret: Optional[str] = None):
+    """Dispatch to multiple URLs concurrently using threads."""
+    results = []
+    threads = []
+
+    def _send(url):
+        result = dispatch_webhook_sync(url, event_type, payload, secret=secret)
+        results.append({"url": url, **result})
+
+    for url in target_urls:
+        t = threading.Thread(target=_send, args=(url,))
+        t.start()
+        threads.append(t)
+
+    for t in threads:
+        t.join(timeout=15)
+
+    return results