feat(models): widen Site struct and DB schema for ping, port, dns, group monitor types

Add Hostname, Port, Timeout, Method, Description, ParentID, AcceptedCodes,
DNSResolveType, DNSServer, and IgnoreTLS fields. Refactor AddSite/UpdateSite
to accept models.Site instead of individual params. Includes DB migrations
for existing databases, per-monitor timeout/TLS in the engine, new type
options in TUI forms, and TYPE column in the sites table.

internal/store/store.go

@@ -9,8 +9,8 @@ type Store interface {
 
 	// Sites
 	GetSites() []models.Site
-	AddSite(name, url, sType string, interval, alertID int, checkSSL bool, threshold, retries int)
-	UpdateSite(id int, name, url, sType string, interval, alertID int, checkSSL bool, threshold, retries int)
+	AddSite(site models.Site)
+	UpdateSite(site models.Site)
 	DeleteSite(id int)
 
 	// Alerts