feat: admin area with customers, users, settings, audit log, service status (phase 5)

- customer CRUD wizard backend: per-system credential shapes validated via
  connector construction, AES-256-GCM at rest, write-only over the API
- ticketing connectors (jira/azure_devops/youtrack/demo) with test-connection
- user management: roles, disable (revokes sessions), force password reset,
  delete; self-demotion/disable/delete guards
- admin-editable runtime settings ({_id:app}) incl. atomizer URL override
- audit log written on every privileged mutation + filterable list API
- service status panel: mongo/atomizer/work-performer health + latency with
  late-bound breaker, sync and jobs status providers
- tabbed admin UI (customers wizard dialog, users table, settings, status, audit)
- compose: mongo nofile ulimit 64000 (1024 default crashed WiredTiger)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

internal/http/providers.go

@@ -0,0 +1,55 @@
+package httpx
+
+import "context"
+
+// Late-bound providers: these are wired by later subsystems (atomizer
+// client, work-performer client, sync manager, job runner) after the server
+// is constructed. All accessors are nil-safe so the admin status panel
+// degrades gracefully while subsystems are absent (e.g. in tests).
+
+// BreakerInfo exposes a circuit breaker's state for the status panel.
+type BreakerInfo interface {
+	BreakerState() string // closed | open | half-open
+}
+
+// StatusProvider returns arbitrary JSON-marshalable status payloads.
+type StatusProvider interface {
+	Statuses() any
+}
+
+func (s *Server) SetAtomizerInfo(b BreakerInfo)  { s.atomizer = b }
+func (s *Server) SetPerformerInfo(b BreakerInfo) { s.performer = b }
+
+// SetSyncTrigger wires the sync manager's "sync now" entry point.
+func (s *Server) SetSyncTrigger(f func(customerID string)) { s.syncTrigger = f }
+func (s *Server) SetSyncStatusProvider(p StatusProvider) {
+	s.syncProvider = p
+}
+func (s *Server) SetJobsStatusProvider(p StatusProvider) {
+	s.jobsProvider = p
+}
+
+func (s *Server) syncStatuses() any {
+	if s.syncProvider == nil {
+		return []any{}
+	}
+	return s.syncProvider.Statuses()
+}
+
+func (s *Server) jobStatuses() any {
+	if s.jobsProvider == nil {
+		return map[string]any{}
+	}
+	return s.jobsProvider.Statuses()
+}
+
+// effectiveAtomizerBaseURL honors the admin settings override (§3) over the
+// env default.
+func (s *Server) effectiveAtomizerBaseURL(ctx context.Context) string {
+	if s.store != nil {
+		if st, err := s.store.GetSettings(ctx); err == nil && st.AtomizerBaseURLOverride != "" {
+			return st.AtomizerBaseURLOverride
+		}
+	}
+	return s.cfg.AtomizerBaseURL
+}