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.

2 files changed, 198 insertions, 0 deletions

diff --git a/src/features/mcp/logic/view-model.test.ts b/src/features/mcp/logic/view-model.test.ts
new file mode 100644
index 0000000..23bf20f
--- /dev/null
+++ b/src/features/mcp/logic/view-model.test.ts
@@ -0,0 +1,88 @@
+import type { McpServerInfo } from "@dispatch/transport-contract";
+import { describe, expect, it } from "vitest";
+import { summarizeMcpServers, viewMcpServer, viewMcpServers } from "./view-model";
+
+const server = (over: Partial<McpServerInfo> = {}): McpServerInfo => ({
+	id: "freecad",
+	state: "connected",
+	toolCount: 12,
+	...over,
+});
+
+describe("viewMcpServer", () => {
+	it("connected → success badge, not busy, no error, passes toolCount", () => {
+		const v = viewMcpServer(server({ toolCount: 5 }));
+		expect(v.badge).toBe("success");
+		expect(v.statusLabel).toBe("Connected");
+		expect(v.busy).toBe(false);
+		expect(v.error).toBeNull();
+		expect(v.toolCount).toBe(5);
+		expect(v.configSource).toBeNull();
+	});
+
+	it("connecting → warning badge + busy (spinner)", () => {
+		const v = viewMcpServer(server({ state: "connecting" }));
+		expect(v.badge).toBe("warning");
+		expect(v.statusLabel).toBe("Connecting…");
+		expect(v.busy).toBe(true);
+		expect(v.error).toBeNull();
+	});
+
+	it("disconnected → neutral badge, not busy", () => {
+		const v = viewMcpServer(server({ state: "disconnected" }));
+		expect(v.badge).toBe("neutral");
+		expect(v.statusLabel).toBe("Disconnected");
+		expect(v.busy).toBe(false);
+		expect(v.error).toBeNull();
+	});
+
+	it("error → error badge + surfaces the reason (with a fallback)", () => {
+		const withReason = viewMcpServer(server({ state: "error", error: "ENOENT: npx" }));
+		expect(withReason.badge).toBe("error");
+		expect(withReason.busy).toBe(false);
+		expect(withReason.error).toBe("ENOENT: npx");
+
+		const noReason = viewMcpServer(server({ state: "error" }));
+		expect(noReason.error).toBe("Failed to connect");
+	});
+
+	it("passes through configSource when present", () => {
+		const v = viewMcpServer(server({ configSource: ".dispatch/mcp.json" }));
+		expect(v.configSource).toBe(".dispatch/mcp.json");
+	});
+
+	it("viewMcpServers maps a list preserving order", () => {
+		const views = viewMcpServers([server({ id: "a" }), server({ id: "b" })]);
+		expect(views.map((v) => v.id)).toEqual(["a", "b"]);
+	});
+});
+
+describe("summarizeMcpServers", () => {
+	it("empty list", () => {
+		expect(summarizeMcpServers([])).toBe("No MCP servers");
+	});
+
+	it("counts connected / connecting / disconnected / errors", () => {
+		expect(summarizeMcpServers([server({ state: "connected" })])).toBe("1 connected");
+		expect(
+			summarizeMcpServers([
+				server({ id: "a", state: "connected" }),
+				server({ id: "b", state: "error" }),
+			]),
+		).toBe("1 connected, 1 error");
+		expect(
+			summarizeMcpServers([
+				server({ id: "a", state: "connected" }),
+				server({ id: "b", state: "connecting" }),
+				server({ id: "c", state: "disconnected" }),
+				server({ id: "d", state: "error" }),
+				server({ id: "e", state: "error" }),
+			]),
+		).toBe("1 connected, 1 connecting, 1 disconnected, 2 errors");
+	});
+
+	it("lists only non-zero buckets", () => {
+		expect(summarizeMcpServers([server({ state: "disconnected" })])).toBe("1 disconnected");
+		expect(summarizeMcpServers([server({ id: "a", state: "connecting" })])).toBe("1 connecting");
+	});
+});
diff --git a/src/features/mcp/logic/view-model.ts b/src/features/mcp/logic/view-model.ts
new file mode 100644
index 0000000..247f804
--- /dev/null
+++ b/src/features/mcp/logic/view-model.ts
@@ -0,0 +1,110 @@
+import type { McpServerInfo, McpServerState } from "@dispatch/transport-contract";
+
+/**
+ * Pure core for the mcp feature — zero DOM, zero effects, zero Svelte.
+ *
+ * The mcp feature exposes the live status of the MCP (Model Context Protocol)
+ * servers configured for a conversation's working directory, fetched from
+ * `GET /conversations/:id/mcp`. This module holds the pure logic: the mapping
+ * of a backend `McpServerState` to a display badge + label, and a one-line
+ * server summary. The effect (the HTTP get MCP status) is INJECTED via the
+ * `LoadMcpStatus` port below; the composition root implements it.
+ */
+
+// ── Injected port (consumer-defines-port; the composition root adapts the
+//    store's HTTP call to this shape). ──────────────────────────────────────────
+
+/** Outcome of `GET /conversations/:id/mcp`; `null` when no real conversation is focused. */
+export type McpStatusResult =
+	| { readonly ok: true; readonly cwd: string | null; readonly servers: readonly McpServerInfo[] }
+	| { readonly ok: false; readonly error: string };
+
+export type LoadMcpStatus = () => Promise<McpStatusResult | null>;
+
+// ── MCP server status → display view ───────────────────────────────────────────
+
+export type Badge = "success" | "warning" | "error" | "neutral";
+
+export interface McpServerView {
+	readonly id: string;
+	readonly state: McpServerState;
+	readonly statusLabel: string;
+	readonly badge: Badge;
+	/** True while the state is transient (show a spinner). */
+	readonly busy: boolean;
+	/** The error reason when `state === "error"`, else null. */
+	readonly error: string | null;
+	/** Number of tools discovered from this server. */
+	readonly toolCount: number;
+	/** Which config source the server was resolved from, else null. */
+	readonly configSource: string | null;
+}
+
+/**
+ * Map a server's state to a display label + badge severity + busy flag. Mirrors
+ * the LSP status visual treatment: `connected` → success, `connecting` (the
+ * transient state, analogous to LSP's `starting`) → warning + spinner, `error`
+ * → error, and `disconnected` (a stable idle state) → neutral.
+ */
+export function viewMcpServer(server: McpServerInfo): McpServerView {
+	let statusLabel: string;
+	let badge: Badge;
+	let busy = false;
+	switch (server.state) {
+		case "connected":
+			statusLabel = "Connected";
+			badge = "success";
+			break;
+		case "connecting":
+			statusLabel = "Connecting…";
+			badge = "warning";
+			busy = true;
+			break;
+		case "disconnected":
+			statusLabel = "Disconnected";
+			badge = "neutral";
+			break;
+		case "error":
+			statusLabel = "Error";
+			badge = "error";
+			break;
+	}
+	return {
+		id: server.id,
+		state: server.state,
+		statusLabel,
+		badge,
+		busy,
+		error: server.state === "error" ? (server.error ?? "Failed to connect") : null,
+		toolCount: server.toolCount,
+		configSource: server.configSource ?? null,
+	};
+}
+
+export function viewMcpServers(servers: readonly McpServerInfo[]): readonly McpServerView[] {
+	return servers.map(viewMcpServer);
+}
+
+/**
+ * A short one-line summary, e.g. "2 connected" / "1 connected, 1 connecting,
+ * 1 error". Only non-zero buckets are listed.
+ */
+export function summarizeMcpServers(servers: readonly McpServerInfo[]): string {
+	if (servers.length === 0) return "No MCP servers";
+	let connected = 0;
+	let connecting = 0;
+	let disconnected = 0;
+	let errored = 0;
+	for (const s of servers) {
+		if (s.state === "connected") connected++;
+		else if (s.state === "error") errored++;
+		else if (s.state === "connecting") connecting++;
+		else disconnected++;
+	}
+	const parts: string[] = [];
+	if (connected > 0) parts.push(`${connected} connected`);
+	if (connecting > 0) parts.push(`${connecting} connecting`);
+	if (disconnected > 0) parts.push(`${disconnected} disconnected`);
+	if (errored > 0) parts.push(`${errored} error${errored === 1 ? "" : "s"}`);
+	return parts.join(", ");
+}