feat: implement journal stream via Shared Worker

Move MQTT connection and message log management to a Shared Worker
using Comlink. This allows multiple browser tabs to share a single
connection and synchronized state.

package-lock.json

@@ -14,6 +14,7 @@
         "@thisbeyond/solid-dnd": "^0.7.5",
         "aedes": "^1.1.1",
         "chokidar": "^5.0.0",
+        "comlink": "^4.4.2",
         "commander": "^14.0.3",
         "csv-parse": "^6.1.0",
         "csv-stringify": "^6.7.0",
@@ -4332,6 +4333,12 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/comlink": {
+      "version": "4.4.2",
+      "resolved": "https://registry.npmjs.org/comlink/-/comlink-4.4.2.tgz",
+      "integrity": "sha512-OxGdvBmJuNKSCMO4NTl1L47VRp6xn2wG4F/2hYzB6tiCb709otOxtEYCSvK80PtjODfXXZu8ds+Nw5kVCjqd2g==",
+      "license": "Apache-2.0"
+    },
     "node_modules/commander": {
       "version": "14.0.3",
       "resolved": "https://registry.npmjs.org/commander/-/commander-14.0.3.tgz",