Phase 1: Cluster-Fundament – Nachrichten, Registry, Paarung, Discovery

- hms_cluster: ClusterMessage (§6.5: Pflichtfelder, Sequenzen, Revisionen,
  execute_at, Trace-ID), CommandTracker (idempotent, vorwärts-only:
  accepted->armed->executed/failed)
- NodeRegistry: online/degraded/stale/offline über Schwellen, UI-Kategorien
  discovered/paired/unknown/incompatible/offline, Doppel-Node-ID blockiert,
  IP-Wechsel erhaelt node_id (§6.3, §6.5)
- Pairing: PIN (TTL 120s, Versuchslimit), Fingerprint (SHA-256 gruppiert),
  Token nur als Hash, Scopes read/control/content_sync/admin, Ablauf +
  sofortiger Widerruf (§6.3, §27.1, ADR-0010)
- Discovery-Modell: _hmsmedia._tcp.local. TXT ohne Secrets, Capability-
  Digest, persistente manuelle Fallback-Liste (ADR-0009)
- ADR-0009 (mDNS + Fallback) und ADR-0010 (Paarung) dokumentiert
- 25 Unit-Tests; Gesamtsuite 183 Tests gruen, Ruff gruen

packages/cluster/hms_cluster/__init__.py

@@ -0,0 +1,54 @@
+"""hms_cluster – Clusterprotokoll, Node-Registry, Paarung, Discovery
+(PLAN.md §6.3, §6.5; ADR-0009, ADR-0010)."""
+
+from hms_cluster.discovery import (
+    DISCOVERY_PROTOCOL_VERSION,
+    SERVICE_TYPE,
+    ManualNodeList,
+    ServiceInfo,
+    capability_digest,
+)
+from hms_cluster.message import ClusterMessage, CommandStatus, CommandTracker
+from hms_cluster.pairing import (
+    PairingPin,
+    PairingStore,
+    Scope,
+    generate_pin,
+    hash_token,
+    identity_fingerprint,
+    new_token,
+    pin_valid,
+)
+from hms_cluster.registry import (
+    DuplicateNodeError,
+    HealthThresholds,
+    NodeCategory,
+    NodeEntry,
+    NodeHealth,
+    NodeRegistry,
+)
+
+__all__ = [
+    "SERVICE_TYPE",
+    "DISCOVERY_PROTOCOL_VERSION",
+    "ServiceInfo",
+    "ManualNodeList",
+    "capability_digest",
+    "ClusterMessage",
+    "CommandStatus",
+    "CommandTracker",
+    "PairingPin",
+    "PairingStore",
+    "Scope",
+    "generate_pin",
+    "pin_valid",
+    "identity_fingerprint",
+    "new_token",
+    "hash_token",
+    "DuplicateNodeError",
+    "HealthThresholds",
+    "NodeCategory",
+    "NodeEntry",
+    "NodeHealth",
+    "NodeRegistry",
+]