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/migrations/v3.6_dropshipping.sql

@@ -0,0 +1,18 @@
+-- ============================================================
+-- v3.6 Dropshipping API Integration
+-- ============================================================
+-- Adds config keys and webhook targets for external
+-- dropshipping platforms.
+-- ============================================================
+
+-- Webhook targets for dropshipping notifications per tenant
+CREATE TABLE IF NOT EXISTS dropshipping_webhooks (
+    id          SERIAL PRIMARY KEY,
+    event_type  VARCHAR(30) NOT NULL,  -- stock_updated, price_updated, sale_made
+    target_url  TEXT NOT NULL,
+    is_active   BOOLEAN DEFAULT true,
+    created_at  TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_dropshipping_webhooks_event
+    ON dropshipping_webhooks(event_type) WHERE is_active = true;