chore: remove root long and rolldown deps (#22481)

* chore(deadcode): add deadcode scanning and remove unused lockfile deps

* chore(changelog): mention deadcode CI scan pass

* ci: disable deadcode job temporarily

* docs(changelog): add PR ref and thanks for deadcode scan entry

* ci: comment out deadcode job condition while keeping it disabled

* Deps: remove dead root dependency from package manifest

* Changelog: reference PR for deadcode dependency cleanup

* Deps: remove unused root signal-utils

* Chore: remove unused lit context deps

* Chore: remove unused root lit dependency

* Chore: remove root long and rolldown deps

* Chore: add changelog for root long/rolldown removal

* Chore: fix a2ui bundling after root lit dependency removal

* Chore: simplify a2ui bundle script dependencies

ui/package.json

@@ -9,10 +9,14 @@
     "test": "vitest run --config vitest.config.ts"
   },
   "dependencies": {
+    "@lit-labs/signals": "^0.1.3",
+    "@lit/context": "^1.1.4",
     "@noble/ed25519": "3.0.0",
     "dompurify": "^3.3.1",
     "lit": "^3.3.2",
     "marked": "^17.0.3",
+    "signal-polyfill": "^0.2.2",
+    "signal-utils": "^0.21.1",
     "vite": "7.3.1"
   },
   "devDependencies": {