Security improvements, role in user creation, todo filters fix

- Remove better-auth dependency (unused)
- Update JWT secrets to stronger values
- Add ENCRYPTION_SALT env variable for password encryption
- Add role field to createUserSchema validator
- Accept role from body in admin.controller createUser
- Fix todo filters: add priority filter, handle completed param
- Remove .env.example (merged into .env)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/services/todo.service.js

@@ -8,7 +8,7 @@ import { NotFoundError } from '../utils/errors.js';
  * Optionally filter by search, project, company, assigned user, or status
  */
 export const getAllTodos = async (filters = {}) => {
-  const { searchTerm, projectId, companyId, assignedTo, status } = filters;
+  const { searchTerm, projectId, companyId, assignedTo, status, priority } = filters;
 
   // If filtering by assignedTo, we need to join with todo_users
   if (assignedTo) {
@@ -48,6 +48,10 @@ export const getAllTodos = async (filters = {}) => {
       conditions.push(eq(todos.status, status));
     }
 
+    if (priority) {
+      conditions.push(eq(todos.priority, priority));
+    }
+
     if (conditions.length > 0) {
       query = query.where(and(...conditions));
     }
@@ -119,6 +123,10 @@ export const getAllTodos = async (filters = {}) => {
     conditions.push(eq(todos.status, status));
   }
 
+  if (priority) {
+    conditions.push(eq(todos.priority, priority));
+  }
+
   if (conditions.length > 0) {
     query = query.where(and(...conditions));
   }