Merge lead-47's L3 mesh-delivery head 710c4032 into the registry builder

The builder keeps both: the registry's versions, floor, tag asks and findings, and ADR 0618's engine-reads state,
its tool builder_engine_reads, the node-engine seat's manifest-reads verb and manifest-reads-changed event.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

modules/mesh-delivery-builder/module.json

@@ -7,6 +7,7 @@
     "builder_ask_again",
     "builder_build_again",
     "builder_builds_since",
+    "builder_engine_reads",
     "builder_floor_again",
     "builder_floor_waits",
     "builder_publish_again",
@@ -36,6 +37,7 @@
     "mesh-delivery-checker.tag-wanted",
     "mesh-delivery-forge-bridge.forge.**",
     "mesh-delivery-indexer.manifest-accepted",
+    "node-engine.manifest-reads-changed",
     "npm-package-registry.published",
     "npm-package-registry.refused",
     "npm-package-registry.removed",
@@ -51,6 +53,7 @@
     "seat:go-package-registry.remove",
     "seat:go-package-registry.versions",
     "seat:mesh-artifact-sweep.held",
+    "seat:node-engine.manifest-reads",
     "seat:npm-package-registry.remove",
     "seat:npm-package-registry.versions",
     "seat:oci-artifact-registry.remove",
@@ -58,6 +61,7 @@
   ],
   "state": [
     { "name": "builds", "history": 5 },
+    { "name": "engine-reads", "history": 1 },
     { "name": "findings", "history": 5 },
     { "name": "floor-waits", "history": 1 },
     { "name": "hearing", "history": 1 },