Fix 9 backend bugs: pricing, zones, geocoding, device tokens, assignment retry

- pricingid null: lookupDoormilePrice now returns matched rule ID; wired to BookingServiceOption.Pricingid
- Zone rename: Interstate→Regional, OtherState→National throughout (code + DB migrated)
- Zone from pincodes: CheckPrice now accepts pickup_pincode+delivery_pincode and auto-resolves zone
- Delivery geocoding: pincodeToLatLon() maps 3-digit prefix to city coords when lat/lon are 0
- Device tokens: device_token field added to PinVerify DTOs; saved on both customer and miler login
- Assignment retry: RejectMilerAssignment now re-triggers AssignCustomerMiler/AssignCRMMiler immediately
- Provider empty B2C: defaults to Doormile when no pricing provider row matches
- City gate 422→400: StatusUnprocessableEntity corrected to StatusBadRequest
- Miler GPS 0,0: WS tracking falls back to MilerProfile DB coords when Redis key is expired

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

controllers/pricing_helpers.go

@@ -46,17 +46,44 @@ func pincodeToState(pincode string) string {
 }
 
 // resolveZone determines the DoormilePricing zone from pickup and delivery pincodes.
-//   - Local     — same 3-digit prefix (same city/sorting district)
-//   - Interstate — different city, same state
-//   - OtherState — different state
+//   - Local    — same 3-digit prefix (same city/sorting district)
+//   - Regional — different city, same state
+//   - National — different state
 func resolveZone(pickupPincode, deliveryPincode string) string {
 	if len(pickupPincode) >= 3 && len(deliveryPincode) >= 3 && pickupPincode[:3] == deliveryPincode[:3] {
 		return "Local"
 	}
 	if pincodeToState(pickupPincode) == pincodeToState(deliveryPincode) {
-		return "Interstate"
+		return "Regional"
 	}
-	return "OtherState"
+	return "National"
+}
+
+// pincodeToLatLon returns approximate coordinates for a pincode using its
+// 3-digit postal division. Returns ok=false for unrecognised pincodes.
+func pincodeToLatLon(pincode string) (lat, lon float64, ok bool) {
+	if len(pincode) < 3 {
+		return
+	}
+	p, err := strconv.Atoi(pincode[:3])
+	if err != nil {
+		return
+	}
+	switch {
+	case p >= 500 && p <= 535:
+		return 17.385044, 78.486671, true // Hyderabad / Telangana
+	case p >= 560 && p <= 591:
+		return 12.971599, 77.594566, true // Bengaluru / Karnataka
+	case p >= 600 && p <= 643:
+		return 13.082680, 80.270718, true // Chennai / Tamil Nadu
+	case p >= 670 && p <= 695:
+		return 10.850516, 76.271080, true // Kerala
+	case p >= 380 && p <= 396:
+		return 23.022505, 72.571365, true // Ahmedabad / Gujarat
+	case p >= 400 && p <= 444:
+		return 19.075984, 72.877656, true // Mumbai / Maharashtra
+	}
+	return
 }
 
 // normalizePricingCategory returns a DoormilePricing-compatible category string.
@@ -81,8 +108,8 @@ func mapServiceTypeToPricing(serviceType string) string {
 
 // lookupDoormilePrice fetches pricing for the given zone/serviceType/weight/category
 // from Redis first, falling back to Postgres on a cache miss.
-// Returns the midpoint of the matched price band and true, or 0 and false if no rule matches.
-func lookupDoormilePrice(zone, pricingServiceType string, weight float64, category string) (float64, bool) {
+// Returns (midpoint price, pricingID, true) on match, or (0, nil, false) when no rule matches.
+func lookupDoormilePrice(zone, pricingServiceType string, weight float64, category string) (float64, *int, bool) {
 	var allRules []models.DoormilePricing
 
 	if db.Rdb != nil {
@@ -102,7 +129,7 @@ func lookupDoormilePrice(zone, pricingServiceType string, weight float64, catego
 		var err error
 		allRules, err = loadFromPostgres(zone, pricingServiceType)
 		if err != nil || len(allRules) == 0 {
-			return 0, false
+			return 0, nil, false
 		}
 	}
 
@@ -111,9 +138,10 @@ func lookupDoormilePrice(zone, pricingServiceType string, weight float64, catego
 		matched = applyFilters(allRules, weight, "General")
 	}
 	if len(matched) == 0 {
-		return 0, false
+		return 0, nil, false
 	}
 
 	rule := matched[0]
-	return (rule.Minprice + rule.Maxprice) / 2, true
+	id := rule.Doormile_pricing_id
+	return (rule.Minprice + rule.Maxprice) / 2, &id, true
 }