feat: Portal, Email Inbound, Discuss + module improvements

- Portal: /my/* routes, signup, password reset, portal user support
- Email Inbound: IMAP polling (go-imap/v2), thread matching
- Discuss: mail.channel, long-polling bus, DM, unread count
- Cron: ir.cron runner (goroutine scheduler)
- Bank Import, CSV/Excel Import
- Automation (ir.actions.server)
- Fetchmail service
- HR Payroll model
- Various fixes across account, sale, stock, purchase, crm, hr, project

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

addons/purchase/models/init.go

@@ -1,12 +1,15 @@
 package models
 
 func Init() {
-	initPurchaseOrder()
-	initPurchaseOrderLine()
+	initPurchaseOrder() // also calls initPurchaseOrderLine()
 	initPurchaseAgreement()
 	initPurchaseReport()
+	initProductSupplierInfo()
+	initAccountMoveLinePurchaseExtension()
 	initPurchaseOrderExtension()
+	initPurchaseOrderWorkflow()
 	initPurchaseOrderLineExtension()
 	initResPartnerPurchaseExtension()
 	initPurchaseOrderAmount()
+	initVendorLeadTime()
 }