diff --git a/prisma/migrate.js b/prisma/migrate.js
index e395919..d6b2cd3 100644
--- a/prisma/migrate.js
+++ b/prisma/migrate.js
@@ -231,6 +231,65 @@ async function migrate() {
     console.log('  tenant_symbols table skipped:', e.message)
   }
 
+  // ─── Step 13: Create symbol_templates table ───
+  console.log('  [13] Creating symbol_templates table...')
+  try {
+    await prisma.$executeRawUnsafe(`
+      CREATE TABLE IF NOT EXISTS symbol_templates (
+        id TEXT PRIMARY KEY DEFAULT gen_random_uuid(),
+        "fileKey" TEXT NOT NULL,
+        "originalFilename" TEXT NOT NULL,
+        "displayName" TEXT,
+        "categoryName" TEXT,
+        "svgPath" TEXT,
+        "metadata" JSONB NOT NULL DEFAULT '{}',
+        "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        UNIQUE("fileKey")
+      )
+    `)
+    console.log('  symbol_templates table created (or already exists)')
+  } catch (e) {
+    console.log('  symbol_templates table skipped:', e.message)
+  }
+
+  // ─── Step 14: Create tenant_categories table ───
+  console.log('  [14] Creating tenant_categories table...')
+  try {
+    await prisma.$executeRawUnsafe(`
+      CREATE TABLE IF NOT EXISTS tenant_categories (
+        id TEXT PRIMARY KEY DEFAULT gen_random_uuid(),
+        "name" TEXT NOT NULL,
+        "description" TEXT,
+        "sortOrder" INTEGER NOT NULL DEFAULT 0,
+        "isActive" BOOLEAN NOT NULL DEFAULT true,
+        "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        "tenantId" TEXT NOT NULL REFERENCES tenants(id) ON DELETE CASCADE
+      )
+    `)
+    console.log('  tenant_categories table created (or already exists)')
+  } catch (e) {
+    console.log('  tenant_categories table skipped:', e.message)
+  }
+
+  // ─── Step 15: Extend tenant_symbols with Phase 1 columns ───
+  console.log('  [15] Extending tenant_symbols with Phase 1 columns...')
+  const tenantSymbolColumns = [
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "name" TEXT`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "svgPath" TEXT`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "isUploaded" BOOLEAN NOT NULL DEFAULT false`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "categoryId" TEXT REFERENCES tenant_categories(id) ON DELETE SET NULL`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "migratedFromIconId" TEXT`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP`,
+    `ALTER TABLE tenant_symbols ADD COLUMN IF NOT EXISTS "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP`,
+  ]
+  let tsAdded = 0
+  for (const sql of tenantSymbolColumns) {
+    try { await prisma.$executeRawUnsafe(sql); tsAdded++ } catch (e) { /* ignore */ }
+  }
+  console.log(`  ${tsAdded}/${tenantSymbolColumns.length} tenant_symbol columns added`)
+
   console.log('✅ Database migrations complete')
 }
 
diff --git a/prisma/seed-icons-only.js b/prisma/seed-icons-only.js
index 6e110a5..d9585c6 100644
--- a/prisma/seed-icons-only.js
+++ b/prisma/seed-icons-only.js
@@ -44,11 +44,10 @@ async function main() {
       patterns: ['Massstab', 'Nordrichtung', 'Windrichtung'] },
   ]
 
-  // Delete ALL old system icons (regardless of fileKey pattern)
-  const deleted = await prisma.iconAsset.deleteMany({
-    where: { isSystem: true },
-  })
-  console.log(`🗑️  ${deleted.count} old system icons removed`)
+  // NOTE: We intentionally do NOT delete old system icons here.
+  // TenantSymbol rows reference IconAsset.id via foreign key.
+  // Deleting would either break references (tenant symbols become 404s)
+  // or cascade-delete tenant symbols. Instead we upsert by fileKey.
 
   // Upsert global categories (preserves tenant categories)
   const catMap = {}
@@ -90,6 +89,7 @@ async function main() {
   }
 
   let created = 0
+  let updated = 0
   for (const file of svgFiles) {
     let name = file.replace('.svg', '')
     name = name.replace(/_de$/i, '').replace(/_DE$/i, '').replace(/-de$/i, '')
@@ -99,7 +99,21 @@ async function main() {
     const category = findCategory(file)
 
     const existing = await prisma.iconAsset.findFirst({ where: { fileKey } })
-    if (!existing) {
+    if (existing) {
+      await prisma.iconAsset.update({
+        where: { id: existing.id },
+        data: {
+          name,
+          categoryId: category.id,
+          mimeType: 'image/svg+xml',
+          isSystem: true,
+          isActive: true,
+          width: 48,
+          height: 48,
+        },
+      })
+      updated++
+    } else {
       await prisma.iconAsset.create({
         data: {
           name,
@@ -115,7 +129,7 @@ async function main() {
     }
   }
 
-  console.log(`✅ FKS Signaturen: ${created} new SVG icons created (${svgFiles.length} total)`)
+  console.log(`✅ FKS Signaturen: ${created} created, ${updated} updated (${svgFiles.length} total)`)
 }
 
 main()
diff --git a/prisma/seed.js b/prisma/seed.js
index 0513845..456eb7e 100644
--- a/prisma/seed.js
+++ b/prisma/seed.js
@@ -110,11 +110,10 @@ async function main() {
       patterns: ['Massstab', 'Nordrichtung', 'Windrichtung'] },
   ]
 
-  // Delete ALL old system icons (regardless of fileKey pattern)
-  const deletedIcons = await prisma.iconAsset.deleteMany({
-    where: { isSystem: true },
-  })
-  console.log(`🗑️  ${deletedIcons.count} old system icons removed`)
+  // NOTE: We intentionally do NOT delete old system icons here.
+  // TenantSymbol rows reference IconAsset.id via foreign key.
+  // Deleting would either break references (tenant symbols become 404s)
+  // or cascade-delete tenant symbols. Instead we upsert by fileKey.
 
   // Clean up empty global categories
   const oldGlobalCats = await prisma.iconCategory.findMany({ where: { tenantId: null } })
@@ -163,6 +162,7 @@ async function main() {
   }
 
   let created = 0
+  let updated = 0
   for (const file of svgFiles) {
     // Clean name: remove .svg, remove _de/_DE suffix
     let name = file.replace('.svg', '')
@@ -173,7 +173,21 @@ async function main() {
     const category = findCategory(file)
 
     const existing = await prisma.iconAsset.findFirst({ where: { fileKey } })
-    if (!existing) {
+    if (existing) {
+      await prisma.iconAsset.update({
+        where: { id: existing.id },
+        data: {
+          name,
+          categoryId: category.id,
+          mimeType: 'image/svg+xml',
+          isSystem: true,
+          isActive: true,
+          width: 48,
+          height: 48,
+        },
+      })
+      updated++
+    } else {
       await prisma.iconAsset.create({
         data: {
           name,
@@ -189,7 +203,7 @@ async function main() {
     }
   }
 
-  console.log(`✅ FKS Signaturen: ${created} new icons created (${svgFiles.length} total SVGs)`)
+  console.log(`✅ FKS Signaturen: ${created} created, ${updated} updated (${svgFiles.length} total SVGs)`)
 
   // Create a demo project
   const demoProject = await prisma.project.upsert({