feat: Add company linking to personal contacts

- Add companyId column to personal_contacts table
- Update personal-contact service to include companyName in list
- Add getContactsByCompanyId function for company contacts endpoint
- Add GET /companies/:companyId/contacts endpoint
- Add companyId to contact validation schema

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

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

src/controllers/personal-contact.controller.js

@@ -7,6 +7,7 @@ const normalizePayload = (body) => ({
   phone: body.phone?.trim(),
   email: body.email?.trim(),
   secondaryEmail: body.secondaryEmail?.trim() || null,
+  companyId: body.companyId || null,
 })
 
 export const listPersonalContacts = async (req, res, next) => {
@@ -57,3 +58,13 @@ export const deletePersonalContact = async (req, res, next) => {
     next(error)
   }
 }
+
+export const getContactsByCompany = async (req, res, next) => {
+  try {
+    const { companyId } = req.params
+    const contacts = await personalContactService.getContactsByCompanyId(companyId)
+    res.status(200).json({ success: true, data: contacts })
+  } catch (error) {
+    next(error)
+  }
+}