refactor(console-web): centralize page lifecycle and UI composition

Declare navigation, page metadata, lazy loaders, and keep-alive policy in one registry. Retain primary iframe pages until a continuous inactive TTL expires and expose typed show, hide, and unload events through the Page SDK.

Move business-aware components out of the UI primitive directory, migrate views and Host dialogs to variant primitives and local Tailwind classes, and remove the global component style layer. Keep native dialogs inside the overlay flex context so they remain centered.

Cover iframe expiration, lifecycle dispatch, UI dependency direction, and global style ownership with focused tests.

crates/wasmeld-console/web/src/lib/model.ts

@@ -1,15 +1,5 @@
 import type { BackendEvent, BackendService } from "./api";
 
-export const VIEWS = [
-  "overview",
-  "services",
-  "instances",
-  "wit-packages",
-  "activity",
-  "settings",
-] as const;
-
-export type View = (typeof VIEWS)[number];
 export type ConnectionState = "connecting" | "online" | "offline";
 export type ServiceStatus = "running" | "stopped" | "faulted";
 export type EventTone = "success" | "warning" | "danger" | "neutral";
@@ -47,16 +37,12 @@ export type FormattedInvocationOutput = {
   automatic: boolean;
 };
 
-export const STATUS_META: Record<ServiceStatus, { label: string; className: string }> = {
-  running: { label: "运行中", className: "status-running" },
-  stopped: { label: "已停止", className: "status-stopped" },
-  faulted: { label: "故障", className: "status-faulted" },
+export const STATUS_META: Record<ServiceStatus, { label: string }> = {
+  running: { label: "运行中" },
+  stopped: { label: "已停止" },
+  faulted: { label: "故障" },
 };
 
-export function isView(value: string | null): value is View {
-  return VIEWS.includes(value as View);
-}
-
 export function serviceKey(service: Pick<Service, "id" | "revision">): string {
   return `${service.id}@${service.revision}`;
 }