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, 21 insertions, 0 deletions

diff --git a/src/features/workspaces/index.ts b/src/features/workspaces/index.ts
new file mode 100644
index 0000000..6cc86a3
--- /dev/null
+++ b/src/features/workspaces/index.ts
@@ -0,0 +1,21 @@
+export type { WorkspaceHttp, WorkspaceResult } from "./adapter/http";
+export { createWorkspaceHttp } from "./adapter/http";
+export type { Route } from "./logic/route";
+export {
+	DEFAULT_WORKSPACE_ID,
+	isValidSlug,
+	parsePath,
+	WORKSPACE_SLUG_RE,
+	workspacePath,
+} from "./logic/route";
+export { pageTitle, relativeTime } from "./logic/view-model";
+export type { WorkspaceStore } from "./store.svelte";
+export { createWorkspaceStore } from "./store.svelte";
+export { default as WorkspaceCard } from "./ui/WorkspaceCard.svelte";
+export { default as WorkspacesHome } from "./ui/WorkspacesHome.svelte";
+
+/** Public module manifest — aggregated by the shell's "Loaded Modules" view. */
+export const manifest = {
+	name: "workspaces",
+	description: "URL-driven conversation grouping with a backend-owned default cwd",
+} as const;