feat(03-01): add Module SDK package and Prisma module registry schema

- Create @tessera/module-sdk with TesseraModule, ModuleRoute, ModuleManifest, ModuleCategory types
- Add Module and TenantModuleActivation Prisma models with tenant-scoped unique constraint
- Apply migration add-module-registry to PostgreSQL
- Framework-agnostic ComponentType for lazy-loaded module UIs

apps/api/prisma/schema.prisma

@@ -84,3 +84,29 @@ model LdapFieldMapping {
 
   @@unique([ldapConfigId, ldapField])
 }
+
+model Module {
+  id          String                   @id @default(uuid())
+  slug        String                   @unique
+  name        String
+  version     String
+  category    String
+  description Json
+  icon        String?
+  isSystem    Boolean                  @default(false)
+  createdAt   DateTime                 @default(now())
+  updatedAt   DateTime                 @updatedAt
+  activations TenantModuleActivation[]
+}
+
+model TenantModuleActivation {
+  id          String   @id @default(uuid())
+  tenantId    String
+  moduleId    String
+  isActive    Boolean  @default(true)
+  activatedAt DateTime @default(now())
+  module      Module   @relation(fields: [moduleId], references: [id], onDelete: Cascade)
+
+  @@unique([tenantId, moduleId])
+  @@index([tenantId])
+}