feat(postal): add postal service addon and bundle pending addon work

- New postal-service-addon: per-player mailboxes + post-office send block
  (ActionForm recipient picker, offline notification queue, chunk-load
  retry via tickingarea)
- Commit previously untracked private-chest, home-sign, keep-inventory
  addons and their docker-compose mounts
- Deploy workflow: add postal + previously unwired addons to path filter
  and checkout list; drop easter-egg from deployment
- enabled_packs.json: register postal UUIDs for Lyla + Mya

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

village-evolution-addon/enabled_packs.json

@@ -1,6 +1,14 @@
 {
   "behavior_packs": [
-    {"pack_id": "c7e91f32-4a8b-4d6e-b21c-9f3a05d8e047", "version": [1, 0, 0]}
+    {"pack_id": "c7e91f32-4a8b-4d6e-b21c-9f3a05d8e047", "version": [1, 0, 0]},
+    {"pack_id": "9a3f8d2e-7c5b-4e1a-b9d2-1f6e3c4a8b50", "version": [1, 0, 0]},
+    {"pack_id": "c8e51d72-9a4f-4b3e-b8c1-2f7d3e6a4b80", "version": [1, 0, 0]},
+    {"pack_id": "b4d72e91-8c43-4f1a-95d2-7e3b6c8a0d10", "version": [1, 0, 0]},
+    {"pack_id": "d7a4b9c1-2e3f-4a5b-8c6d-1f2e3d4c5b60", "version": [1, 0, 0]}
   ],
-  "resource_packs": []
+  "resource_packs": [
+    {"pack_id": "9a3f8d2e-7c5b-4e1a-b9d2-1f6e3c4a8b53", "version": [1, 0, 1]},
+    {"pack_id": "c8e51d72-9a4f-4b3e-b8c1-2f7d3e6a4b83", "version": [1, 0, 1]},
+    {"pack_id": "d7a4b9c1-2e3f-4a5b-8c6d-1f2e3d4c5b63", "version": [1, 0, 0]}
+  ]
 }