feat: Add dueDate (date+time) to notes and update reminders to datetime

- Add dueDate timestamp field to notes schema
- Update note validators to accept dueDate
- Update note service to handle dueDate in CRUD operations
- Fix company and project controllers to pass dueDate
- Fix route validations to include dueDate field

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/controllers/company.controller.js

@@ -208,11 +208,12 @@ export const addCompanyNote = async (req, res, next) => {
   try {
     const userId = req.userId;
     const { companyId } = req.params;
-    const { content } = req.body;
+    const { content, dueDate } = req.body;
 
     const note = await noteService.createNote(userId, {
       content,
       companyId,
+      dueDate,
     });
 
     res.status(201).json({
@@ -232,10 +233,11 @@ export const addCompanyNote = async (req, res, next) => {
 export const updateCompanyNote = async (req, res, next) => {
   try {
     const { noteId } = req.params;
-    const { content } = req.body;
+    const { content, dueDate } = req.body;
 
     const note = await noteService.updateNote(noteId, {
       content,
+      dueDate,
     });
 
     res.status(200).json({