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- remove the superseded root TanStack Start application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/.gitignore

@@ -0,0 +1,7 @@
+/node_modules/
+/dist/
+*.tsbuildinfo
+.env*
+!.env.example
+.DS_Store
+*.log