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, 67 insertions, 0 deletions

diff --git a/src/features/workspaces/logic/view-model.test.ts b/src/features/workspaces/logic/view-model.test.ts
new file mode 100644
index 0000000..52f7025
--- /dev/null
+++ b/src/features/workspaces/logic/view-model.test.ts
@@ -0,0 +1,67 @@
+import type { WorkspaceEntry } from "@dispatch/wire";
+import { describe, expect, it } from "vitest";
+import { pageTitle, relativeTime } from "./view-model";
+
+describe("relativeTime", () => {
+	const now = 1_000_000_000_000; // 2001-09-09
+
+	it("is 'now' within a minute", () => {
+		expect(relativeTime(now, now)).toBe("now");
+		expect(relativeTime(now - 59_000, now)).toBe("now");
+	});
+
+	it("is minutes under an hour", () => {
+		expect(relativeTime(now - 5 * 60_000, now)).toBe("5m");
+		expect(relativeTime(now - 59 * 60_000, now)).toBe("59m");
+	});
+
+	it("is hours under a day", () => {
+		expect(relativeTime(now - 2 * 60 * 60_000, now)).toBe("2h");
+	});
+
+	it("is days under a week", () => {
+		expect(relativeTime(now - 3 * 24 * 60 * 60_000, now)).toBe("3d");
+	});
+
+	it("is a short date beyond a week", () => {
+		// 7+ days ago: just check it is a MM/DD string.
+		const s = relativeTime(now - 10 * 24 * 60 * 60_000, now);
+		expect(s).toMatch(/^\d{2}\/\d{2}$/);
+	});
+});
+
+describe("pageTitle", () => {
+	// Minimal valid WorkspaceEntry (the irrelevant metadata is zeroed).
+	const ws = (id: string, title: string): WorkspaceEntry => ({
+		id,
+		title,
+		defaultCwd: null,
+		createdAt: 0,
+		lastActivityAt: 0,
+		conversationCount: 0,
+	});
+
+	it("is 'Dispatch' for the home route", () => {
+		expect(pageTitle({ kind: "home" }, [])).toBe("Dispatch");
+		expect(pageTitle({ kind: "home" }, [ws("default", "Default")])).toBe("Dispatch");
+	});
+
+	it("is 'Dispatch: {title}' for a workspace with a display title", () => {
+		const list = [ws("default", "Default"), ws("my-ws", "My Workspace")];
+		expect(pageTitle({ kind: "workspace", id: "my-ws" }, list)).toBe("Dispatch: My Workspace");
+	});
+
+	it("falls back to the slug (id) until the list has loaded the workspace", () => {
+		expect(pageTitle({ kind: "workspace", id: "pending" }, [])).toBe("Dispatch: pending");
+	});
+
+	it("uses the id as the title when it was never customized (defaults to id)", () => {
+		const list = [ws("default", "default")];
+		expect(pageTitle({ kind: "workspace", id: "default" }, list)).toBe("Dispatch: default");
+	});
+
+	it("matches by id, not title", () => {
+		const list = [ws("a", "shared-title"), ws("b", "shared-title")];
+		expect(pageTitle({ kind: "workspace", id: "b" }, list)).toBe("Dispatch: shared-title");
+	});
+});