feat(console-web): replace TanStack UI with Solid host pages

- move the management frontend under the wasmeld-console crate
- use a persistent Host shell with disposable iframe page documents
- version Host/Page postMessage state and command contracts
- migrate runtime, service, WIT, invocation, and settings workflows
- add Tailwind CSS v4, responsive layouts, and Host-owned dialogs
- emit a dependency-free PWA worker with API cache exclusions
- remove the superseded root TanStack Start application

crates/wasmeld-console/web/public/manifest.webmanifest

@@ -0,0 +1,18 @@
+{
+  "name": "Wasmeld Console",
+  "short_name": "Wasmeld",
+  "description": "WebAssembly Component Runtime management console",
+  "theme_color": "#173f35",
+  "background_color": "#f3f6f5",
+  "display": "standalone",
+  "start_url": "/",
+  "scope": "/",
+  "icons": [
+    {
+      "src": "/icon.svg",
+      "sizes": "any",
+      "type": "image/svg+xml",
+      "purpose": "any maskable"
+    }
+  ]
+}