refactor: remove CurrentPrice from local_components and transition to pricelist-based pricing

## Overview
Removed the CurrentPrice and SyncedAt fields from local_components, transitioning to a
pricelist-based pricing model where all prices are sourced from local_pricelist_items
based on the configuration's selected pricelist.

## Changes

### Data Model Updates
- **LocalComponent**: Now stores only metadata (LotName, LotDescription, Category, Model)
  - Removed: CurrentPrice, SyncedAt (both redundant)
  - Pricing is now exclusively sourced from local_pricelist_items

- **LocalConfiguration**: Added pricelist selection fields
  - Added: WarehousePricelistID, CompetitorPricelistID
  - These complement the existing PricelistID (Estimate)

### Migrations
- Added migration "drop_component_unused_fields" to remove CurrentPrice and SyncedAt columns
- Added migration "add_warehouse_competitor_pricelists" to add new pricelist fields

### Component Sync
- Removed current_price from MariaDB query
- Removed CurrentPrice assignment in component creation
- SyncComponentPrices now exclusively updates based on pricelist_items via quote calculation

### Quote Calculation
- Added PricelistID field to QuoteRequest
- Updated local-first path to use pricelist_items instead of component.CurrentPrice
- Falls back to latest estimate pricelist if PricelistID not specified
- Maintains offline-first behavior: local queries work without MariaDB

### Configuration Refresh
- Removed fallback on component.CurrentPrice
- Prices are only refreshed from local_pricelist_items
- If price not found in pricelist, original price is preserved

### API Changes
- Removed CurrentPrice from ComponentView
- Components API no longer returns pricing information
- Pricing is accessed via QuoteService or PricelistService

### Code Cleanup
- Removed UpdateComponentPricesFromPricelist() method
- Removed EnsureComponentPricesFromPricelists() method
- Updated UnifiedRepository to remove offline pricing logic
- Updated converters to remove CurrentPrice mapping

## Architecture Impact
- Components = metadata store only
- Prices = managed by pricelist system
- Quote calculation = owns all pricing logic
- Local-first behavior preserved: SQLite queries work offline, no MariaDB dependency

## Testing
- Build successful
- All code compiles without errors
- Ready for migration testing with existing databases

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

internal/services/quote.go

@@ -78,6 +78,7 @@ type QuoteRequest struct {
 		LotName  string `json:"lot_name"`
 		Quantity int    `json:"quantity"`
 	} `json:"items"`
+	PricelistID *uint `json:"pricelist_id,omitempty"` // Optional: use specific pricelist for pricing
 }
 
 type PriceLevelsRequest struct {
@@ -123,6 +124,16 @@ func (s *QuoteService) ValidateAndCalculate(req *QuoteRequest) (*QuoteValidation
 			Warnings: make([]string, 0),
 		}
 
+		// Determine which pricelist to use for pricing
+		pricelistID := req.PricelistID
+		if pricelistID == nil || *pricelistID == 0 {
+			// By default, use latest estimate pricelist
+			latestPricelist, err := s.localDB.GetLatestLocalPricelistBySource("estimate")
+			if err == nil && latestPricelist != nil {
+				pricelistID = &latestPricelist.ServerID
+			}
+		}
+
 		var total float64
 		for _, reqItem := range req.Items {
 			localComp, err := s.localDB.GetLocalComponent(reqItem.LotName)
@@ -142,13 +153,19 @@ func (s *QuoteService) ValidateAndCalculate(req *QuoteRequest) (*QuoteValidation
 				TotalPrice:  0,
 			}
 
-			if localComp.CurrentPrice != nil && *localComp.CurrentPrice > 0 {
-				item.UnitPrice = *localComp.CurrentPrice
-				item.TotalPrice = *localComp.CurrentPrice * float64(reqItem.Quantity)
-				item.HasPrice = true
-				total += item.TotalPrice
+			// Get price from pricelist_items
+			if pricelistID != nil {
+				price, found := s.lookupPriceByPricelistID(*pricelistID, reqItem.LotName)
+				if found && price > 0 {
+					item.UnitPrice = price
+					item.TotalPrice = price * float64(reqItem.Quantity)
+					item.HasPrice = true
+					total += item.TotalPrice
+				} else {
+					result.Warnings = append(result.Warnings, "No price available for: "+reqItem.LotName)
+				}
 			} else {
-				result.Warnings = append(result.Warnings, "No price available for: "+reqItem.LotName)
+				result.Warnings = append(result.Warnings, "No pricelist available for: "+reqItem.LotName)
 			}
 
 			result.Items = append(result.Items, item)