fix(db): resolve migration bugs preventing fresh database initialization

- Fix composite primary keys in role_permissions and user_roles tables
  (PostgreSQL does not allow multiple PRIMARY KEY constraints)
- Fix FK table name mismatch: tasks → tokens (was wf_tokens)
- Fix FK table name mismatch: messages → message_templates (was message_templates_ref)
- Fix tenant table name in main.rs SQL: tenant (not tenants)
- Fix React Router nested routes: add /* wildcard for child route matching

crates/erp-server/src/main.rs

@@ -62,7 +62,7 @@ async fn main() -> anyhow::Result<()> {
 
         let existing = TenantId::find_by_statement(sea_orm::Statement::from_string(
             sea_orm::DatabaseBackend::Postgres,
-            "SELECT id FROM tenants WHERE deleted_at IS NULL LIMIT 1".to_string(),
+            "SELECT id FROM tenant WHERE deleted_at IS NULL LIMIT 1".to_string(),
         ))
         .one(&db)
         .await
@@ -79,7 +79,7 @@ async fn main() -> anyhow::Result<()> {
                 // Insert default tenant using raw SQL (no tenant entity in erp-server)
                 db.execute(sea_orm::Statement::from_sql_and_values(
                     sea_orm::DatabaseBackend::Postgres,
-                    "INSERT INTO tenants (id, name, code, status, created_at, updated_at) VALUES ($1, $2, $3, $4, NOW(), NOW())",
+                    "INSERT INTO tenant (id, name, code, status, created_at, updated_at) VALUES ($1, $2, $3, $4, NOW(), NOW())",
                     [
                         new_tenant_id.into(),
                         "Default Tenant".into(),