rebrand + purge orphaned frontend: Chat Switchboard → Switchboard Core

Branding: bulk rename across 50+ files (Go, JS, CSS, HTML, YAML, JSON,
shell scripts). Fix Helm chart description and git repo URLs.
Fix test helper taglines.

Admin surface: strip 14 gutted tabs (providers, models, personas,
roles, knowledge, memory, tasks, health, routing, capabilities,
channels, dashboard, usage, stats). Collapse to 4 categories:
People, Workflows, System, Monitoring.

Settings surface: strip 11 gutted tabs (models, personas, providers,
roles, knowledge, memory, usage, workflows, tasks, data, gitkeys).
Keep: general, appearance, profile, teams, connections, notifications.

Team-admin surface: strip 5 gutted tabs (personas, providers,
knowledge, tasks, usage). Keep: members, groups, connections,
workflows, settings, activity.

Components: delete chat-pane/ (13 files, 1938 lines) and
notes-pane/ (10 files, 2381 lines).

main.go: remove stale Health.Prune maintenance goroutine.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/main.go

@@ -109,21 +109,6 @@ func main() {
 		// v0.33.0: Start Prometheus DB pool collector
 		metrics.StartDBCollector(database.DB, 15*time.Second)
 
-		// Kernel maintenance: prune stale data every 6 hours
-		go func() {
-			ticker := time.NewTicker(6 * time.Hour)
-			defer ticker.Stop()
-			for range ticker.C {
-				ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-				if n, err := stores.Health.Prune(ctx, time.Now().UTC().Add(-7*24*time.Hour)); err != nil {
-					log.Printf("⚠ maintenance prune failed: %v", err)
-				} else if n > 0 {
-					log.Printf("🧹 maintenance: pruned %d stale rows", n)
-				}
-				cancel()
-			}
-		}()
-
 		// Bootstrap admin from env (K8s secret) — upserts on every restart
 		handlers.BootstrapAdmin(cfg, stores, uekCache)