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/component.go

@@ -53,7 +53,6 @@ type ComponentView struct {
 	Category        string                `json:"category"`
 	CategoryName    string                `json:"category_name"`
 	Model           string                `json:"model"`
-	CurrentPrice    *float64              `json:"current_price"`
 	PriceFreshness  models.PriceFreshness `json:"price_freshness"`
 	PopularityScore float64               `json:"popularity_score"`
 	Specs           models.Specs          `json:"specs,omitempty"`
@@ -92,7 +91,6 @@ func (s *ComponentService) List(filter repository.ComponentFilter, page, perPage
 		view := ComponentView{
 			LotName:         c.LotName,
 			Model:           c.Model,
-			CurrentPrice:    c.CurrentPrice,
 			PriceFreshness:  c.GetPriceFreshness(30, 60, 90, 3),
 			PopularityScore: c.PopularityScore,
 			Specs:           c.Specs,
@@ -134,7 +132,6 @@ func (s *ComponentService) GetByLotName(lotName string) (*ComponentView, error)
 	view := &ComponentView{
 		LotName:         c.LotName,
 		Model:           c.Model,
-		CurrentPrice:    c.CurrentPrice,
 		PriceFreshness:  c.GetPriceFreshness(30, 60, 90, 3),
 		PopularityScore: c.PopularityScore,
 		Specs:           c.Specs,