Expand demo seed: 178 inventory items + 30 vendors

Inventory (11 → 178):
- 101 total powders: 6 core + 55 Prismatic + 20 Columbia + 13 Tiger Drylac + 9 Sherwin-Williams
- 77 supplies: 21 masking, 16 chemicals, 16 abrasives, 15 hanging hardware, 9 PPE
- ForceRemoveAll path now deletes all inventory for the company (not just
  the 11 enumerated SKUs), since transactions are pre-swept before this block

Vendors (5 → 30):
- Tiger Drylac, Sherwin-Williams Powders, Eastwood (powder suppliers)
- Clemco, Triangle Abrasives, Airgas, Linde (blasting/gases)
- Duke Energy, AT&T, Spectrum, Raleigh Electric, Carolina Industrial Water (utilities)
- Safety-Kleen, Raleigh Waste (environmental)
- Work N Gear, HD Supply, Carolina Office, First Insurance (services)
- Triangle Commercial Properties LLC (landlord — shop lease with address + terms)
- Fastenal, MSC, McMaster-Carr, Uline, Amazon Business, Lowe's Pro, NAPA (supply chain)

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

src/PowderCoating.Infrastructure/Services/SeedDataService.Remove.cs

@@ -389,18 +389,37 @@ public partial class SeedDataService
             // ── Inventory Items ───────────────────────────────────────────────────
             if (options.InventoryItems)
             {
-                var seededSkus = SeededInventorySkuSuffixes.Select(s => $"{company.CompanyCode}{s}").ToArray();
-                var inventoryItems = await _context.InventoryItems
-                    .IgnoreQueryFilters()
-                    .Where(i => i.CompanyId == companyId && seededSkus.Contains(i.SKU))
-                    .ToListAsync();
+                List<InventoryItem> inventoryItems;
+
+                if (options.ForceRemoveAll)
+                {
+                    // Full reset: wipe all inventory for this company.
+                    // InventoryTransactions were already cleared in the pre-sweep above.
+                    inventoryItems = await _context.InventoryItems
+                        .IgnoreQueryFilters()
+                        .Where(i => i.CompanyId == companyId)
+                        .ToListAsync();
+                }
+                else
+                {
+                    // Selective removal: only remove the 11 core seeded SKUs by fingerprint.
+                    var seededSkus = SeededInventorySkuSuffixes.Select(s => $"{company.CompanyCode}{s}").ToArray();
+                    inventoryItems = await _context.InventoryItems
+                        .IgnoreQueryFilters()
+                        .Where(i => i.CompanyId == companyId && seededSkus.Contains(i.SKU))
+                        .ToListAsync();
+                }
 
                 if (inventoryItems.Any())
                 {
-                    var inventoryIds = inventoryItems.Select(i => i.Id).ToList();
-                    var transactions = await _context.InventoryTransactions.IgnoreQueryFilters()
-                        .Where(t => inventoryIds.Contains(t.InventoryItemId)).ToListAsync();
-                    if (transactions.Any()) _context.InventoryTransactions.RemoveRange(transactions);
+                    if (!options.ForceRemoveAll)
+                    {
+                        // In selective mode transactions weren't pre-swept — remove them now.
+                        var inventoryIds = inventoryItems.Select(i => i.Id).ToList();
+                        var transactions = await _context.InventoryTransactions.IgnoreQueryFilters()
+                            .Where(t => inventoryIds.Contains(t.InventoryItemId)).ToListAsync();
+                        if (transactions.Any()) _context.InventoryTransactions.RemoveRange(transactions);
+                    }
 
                     _context.InventoryItems.RemoveRange(inventoryItems);
                     totalRemoved += inventoryItems.Count;