feat: workspaces shell + cwd-lsp rename + mcp/settings/system-prompt features + app wiring

- workspaces: URL-driven conversation grouping (home listing at /, routing,
  store, http adapter, WorkspaceCard) wired into the App.svelte shell
- rename features/workspace -> features/cwd-lsp (the cwd/lsp status feature)
- new features: mcp (status view), settings (chat-limit field), system-prompt
  (prompt builder), all rendered via the generic surface host
- chat: store + ChatView updates
- tabs: tabs-store updates
- app wiring: ErrorModal (full-screen error surface), app/App.svelte + store.svelte

This commit makes HEAD typecheck clean for the first time: the prior HEAD
(c95cc77) imported features/settings from app/App.svelte but never committed
the feature, so only the full working tree was green.

1 files changed, 69 insertions, 2 deletions

diff --git a/src/App.svelte b/src/App.svelte
index ffd5543..9d06b9f 100644
--- a/src/App.svelte
+++ b/src/App.svelte
@@ -1,7 +1,74 @@
 <script lang="ts">
 	import { App, createAppStore } from "./app";
+	import { createHistoryAdapter } from "./adapters/history";
+	import {
+		createWorkspaceHttp,
+		createWorkspaceStore,
+		pageTitle,
+		parsePath,
+		WorkspacesHome,
+		type Route,
+	} from "./features/workspaces";
+	import { resolveHttpUrl } from "./app/resolve-http-url";
 
-	const store = createAppStore();
+	// Parse the route BEFORE creating the store so the boot draft + active
+	// workspace are correct from the first render (no flash of the "default"
+	// workspace when deep-linking to /<id>).
+	const history = createHistoryAdapter();
+	const initialRoute = parsePath(history.path);
+	const store = createAppStore(
+		initialRoute.kind === "workspace" ? { workspaceId: initialRoute.id } : {},
+	);
+
+	// The workspace HTTP edge shares the same httpBase resolution as the store.
+	const httpBase = resolveHttpUrl(
+		{
+			VITE_HTTP_URL: import.meta.env.VITE_HTTP_URL,
+			VITE_HTTP_PORT: import.meta.env.VITE_HTTP_PORT,
+		},
+		typeof location !== "undefined" ? location : undefined,
+	);
+	const workspaceStore = createWorkspaceStore(
+		createWorkspaceHttp(httpBase, globalThis.fetch.bind(globalThis)),
+	);
+
+	let route = $state<Route>(initialRoute);
+
+	// React to back/forward + programmatic navigation.
+	$effect(() => {
+		return history.subscribe((path) => {
+			route = parsePath(path);
+		});
+	});
+
+	// On entering a workspace: scope the store to it (idempotent — skip if already
+	// scoped) + ensure the workspace exists (create-on-miss, so it appears in the
+	// home list immediately). The backend also auto-creates on `chat.send`.
+	$effect(() => {
+		if (route.kind !== "workspace") return;
+		const id = route.id;
+		if (store.activeWorkspaceId !== id) {
+			store.setActiveWorkspace(id);
+		}
+		void workspaceStore.ensure(id);
+	});
+
+	// Keep the browser tab title in sync with the route: "Dispatch" on the home
+	// page, "Dispatch: {title}" on a workspace page (falling back to the URL slug
+	// until the list loads it). Reads `route` + the workspace list, so it re-runs
+	// on navigation and again once `ensure` refreshes the list.
+	$effect(() => {
+		if (typeof document === "undefined") return;
+		document.title = pageTitle(route, workspaceStore.list);
+	});
+
+	function navigate(path: string): void {
+		history.navigate(path);
+	}
 </script>
 
-<App {store} />
+{#if route.kind === "home"}
+	<WorkspacesHome store={workspaceStore} onNavigate={navigate} />
+{:else}
+	<App {store} />
+{/if}