refactor(server): rename Org to Instance

Adds migration 0004_org_to_instance, the ScopedCollections list, the
AssertNoScopedCollectionMissed boot check, and moves EnsureAuthIndexes into
its own file.

Two ordering constraints the rename exposed, both now enforced and commented:

- 0004 must run BEFORE EnsureAuthIndexes. The index builder creates
  instances.slug, which would create an empty instances collection and make
  0004 refuse to rename orgs onto an existing target.
- Migrations 0001 to 0003 run BEFORE 0004 and still read and write org_id, so
  they use a private legacyOrg struct rather than shared/models.

server/internal/notify/dispatch.go

@@ -1,6 +1,3 @@
-
-
-
 package notify
 
 import (
@@ -10,7 +7,6 @@ import (
 	"github.com/mrhid6/vantage/server/internal/models"
 )
 
-
 type Event struct {
 	MonitorName string
 	Type        string
@@ -20,7 +16,6 @@ type Event struct {
 	Time        time.Time
 }
 
-
 func (e Event) title() string {
 	verb := "recovered"
 	if e.NewStatus == models.StatusDown {
@@ -33,7 +28,6 @@ func (e Event) title() string {
 	return s
 }
 
-
 func Dispatch(ch models.NotificationChannel, ev Event) error {
 	switch ch.Type {
 	case models.ChannelWebhook:
@@ -51,7 +45,6 @@ func Dispatch(ch models.NotificationChannel, ev Event) error {
 	}
 }
 
-
 func Test(ch models.NotificationChannel) error {
 	return Dispatch(ch, Event{
 		MonitorName: "Test monitor",

server/internal/notify/http.go

@@ -28,7 +28,6 @@ func postJSON(target string, payload any) error {
 	return nil
 }
 
-
 func dispatchWebhook(ch models.NotificationChannel, ev Event) error {
 	target := ch.Config["url"]
 	if target == "" {

server/internal/notify/smtp.go

@@ -13,13 +13,6 @@ import (
 
 const smtpTimeout = 15 * time.Second
 
-
-
-
-
-
-
-
 func dispatchSMTP(ch models.NotificationChannel, ev Event) error {
 	host := ch.Config["host"]
 	port := ch.Config["port"]
@@ -36,7 +29,6 @@ func dispatchSMTP(ch models.NotificationChannel, ev Event) error {
 	}
 	_ = conn.SetDeadline(time.Now().Add(smtpTimeout))
 
-	
 	if port == "465" {
 		conn = tls.Client(conn, &tls.Config{ServerName: host})
 	}

server/internal/notify/template.go

@@ -10,7 +10,6 @@ import (
 	"github.com/mrhid6/vantage/server/internal/models"
 )
 
-
 const (
 	colBg        = "#0f1117"
 	colSurface   = "#1a1d27"
@@ -23,7 +22,6 @@ const (
 	colDanger    = "#ef4444"
 )
 
-
 func statusColor(status string) string {
 	switch status {
 	case models.StatusUp:
@@ -35,8 +33,6 @@ func statusColor(status string) string {
 	}
 }
 
-
-
 func buildMIME(from, to, subject, text, htmlBody string) ([]byte, error) {
 	var buf strings.Builder
 	w := multipart.NewWriter(&buf)
@@ -150,7 +146,6 @@ func htmlEmail(ev Event) string {
 	)
 }
 
-
 func textEmail(ev Event) string {
 	return strings.Join([]string{
 		ev.title(),