feat: Labels-Feature vollständig entfernen (PROJ-9)

Backend:
- internal/labelstore/ gelöscht (Store, Schema, CRUD)
- internal/api/label_handlers.go gelöscht (alle Label-Routen)
- internal/api/server.go: labels-Feld + SetLabels() entfernt
- internal/api/search_handlers.go: label_id-Filter + Enrichment entfernt
- internal/index/index.go: LabelID aus SearchRequest entfernt
- internal/imapserver/server.go: labels-Feld + labelbasierte Mailboxen entfernt
- cmd/archivmail/main.go: labelstore-Init + SetLabels() entfernt
- cmd/archivmail/version.go: labelstore-Modul entfernt, index-Kommentar korrigiert

Frontend:
- LabelList.tsx, LabelPicker.tsx, LabelsTab.tsx gelöscht
- src/lib/api/system.ts: MailLabel/LabelRule-Typen + alle Label-Funktionen entfernt
- src/lib/api/index.ts: Label-Exports entfernt
- src/app/search/page.tsx: LabelList + selectedLabelId State entfernt
- src/app/mail/[id]/page.tsx: LabelPicker + Labels-State entfernt
- src/app/admin/page.tsx: LabelsTab + alle Label-Handler/State entfernt

Docs:
- features/PROJ-9: Status auf Removed gesetzt
- features/INDEX.md: PROJ-9 auf Removed gesetzt

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

cmd/archivmail/main.go

@@ -27,7 +27,6 @@ import (
 	imapstore "github.com/archivmail/internal/imap"
 	"github.com/archivmail/internal/imapserver"
 	"github.com/archivmail/internal/index"
-	"github.com/archivmail/internal/labelstore"
 	ldapcfg "github.com/archivmail/internal/ldapconfig"
 	"github.com/archivmail/internal/mailer"
 	pop3store "github.com/archivmail/internal/pop3"
@@ -264,19 +263,10 @@ func main() {
 	srv.SetTenants(tenantSt)
 	srv.SetIndexManager(idxMgr)
 
-	// PROJ-9: Label store
-	labelSt, err := labelstore.New(cfg.Database.DSN())
-	if err != nil {
-		logger.Error("label store init failed", "err", err)
-		os.Exit(1)
-	}
-	defer labelSt.Close()
-	srv.SetLabels(labelSt)
-
 	// PROJ-26: IMAP Archive Server (read-only access for IMAP clients)
 	if cfg.IMAPServer.Enabled {
 		cfg.IMAPServer.FQDN = cfg.Server.FQDN
-		imapSrv := imapserver.New(cfg.IMAPServer, mailStore, users, labelSt, audlog, authMgr, logger, tenantSt)
+		imapSrv := imapserver.New(cfg.IMAPServer, mailStore, users, audlog, authMgr, logger, tenantSt)
 		if err := imapSrv.Start(); err != nil {
 			logger.Error("IMAP server failed to start", "err", err)
 			os.Exit(1)

cmd/archivmail/version.go

@@ -17,11 +17,10 @@ var Modules = map[string]string{
 	"imapserver":  "1.3", // PROJ-28 FQDN-Greeting (RFC 3501)
 	"auth":        "1.3", // JWT, bcrypt cost 12, TOTP
 	"audit":       "1.1", // PostgreSQL append-only, QueryFilter
-	"index":       "1.0", // Xapian-Wrapper, Async-Worker, Tenant-Index
+	"index":       "1.1", // Manticore RT-Index, Async-Worker, Tenant-Index
 	"api":         "1.8", // PROJ-34 Retention-API + pro-Mandant Endpoints
 	"userstore":   "1.3", // domain_auditor Rolle, bcrypt, LDAP-Auth
 	"imap":        "1.2", // IMAP-Sync, Scheduler, POP3
-	"labelstore":  "1.0", // Labels, Tenant-Isolation
 	"tenantstore": "1.3", // PROJ-34 retention_days, GetRetentionDays, SetRetentionDays
 	"ldapconfig":  "1.1", // Pro-Mandant LDAP, TLS
 	"mailparser":  "1.1", // RFC-2822, MIME, MessageID-Extraktion