feat(console-web): add bounded iframe keep-alive

- opt service and settings pages into document retention
- preserve iframe identity and local Solid state across navigation
- cap retained documents with deterministic LRU eviction
- deliver activate, deactivate, and dispose lifecycle messages
- reject commands emitted by inactive page documents
- expose page activity as a Solid accessor
- test retention, recreation, eviction, and invalid limits

crates/wasmeld-console/web/package.json

@@ -7,7 +7,7 @@
     "dev": "vite dev",
     "build": "vite build && tsc --noEmit",
     "preview": "vite preview",
-    "test": "npm run build && node --test tests/build-output.test.mjs",
+    "test": "npm run build && node --experimental-strip-types --test tests/*.test.mjs",
     "lint": "oxlint . --deny-warnings",
     "format": "oxfmt .",
     "format:check": "oxfmt --check ."