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/sync/service.go

@@ -346,17 +346,10 @@ func (s *Service) SyncPricelists() (int, error) {
 	}
 
 	synced := 0
-	var latestEstimateLocalID uint
-	var latestEstimateCreatedAt time.Time
 	for _, pl := range serverPricelists {
 		// Check if pricelist already exists locally
 		existing, _ := s.localDB.GetLocalPricelistByServerID(pl.ID)
 		if existing != nil {
-			// Track latest estimate pricelist by created_at for component refresh.
-			if pl.Source == string(models.PricelistSourceEstimate) && (latestEstimateCreatedAt.IsZero() || pl.CreatedAt.After(latestEstimateCreatedAt)) {
-				latestEstimateCreatedAt = pl.CreatedAt
-				latestEstimateLocalID = existing.ID
-			}
 			continue
 		}
 
@@ -385,10 +378,6 @@ func (s *Service) SyncPricelists() (int, error) {
 			slog.Debug("synced pricelist with items", "version", pl.Version, "items", itemCount)
 		}
 
-		if pl.Source == string(models.PricelistSourceEstimate) && (latestEstimateCreatedAt.IsZero() || pl.CreatedAt.After(latestEstimateCreatedAt)) {
-			latestEstimateCreatedAt = pl.CreatedAt
-			latestEstimateLocalID = localPL.ID
-		}
 		synced++
 	}
 
@@ -399,16 +388,6 @@ func (s *Service) SyncPricelists() (int, error) {
 		slog.Info("deleted stale local pricelists", "deleted", removed)
 	}
 
-	// Update component prices from latest estimate pricelist only.
-	if latestEstimateLocalID > 0 {
-		updated, err := s.localDB.UpdateComponentPricesFromPricelist(latestEstimateLocalID)
-		if err != nil {
-			slog.Warn("failed to update component prices from pricelist", "error", err)
-		} else {
-			slog.Info("updated component prices from latest pricelist", "updated", updated)
-		}
-	}
-
 	// Update last sync time
 	s.localDB.SetLastSyncTime(time.Now())
 	s.RecordSyncHeartbeat()