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
(dfe1711) imported features/settings from app/App.svelte but never committed
the feature, so only the full working tree was green.

1 files changed, 77 insertions, 0 deletions

diff --git a/src/features/workspaces/logic/route.test.ts b/src/features/workspaces/logic/route.test.ts
new file mode 100644
index 0000000..a6da3e1
--- /dev/null
+++ b/src/features/workspaces/logic/route.test.ts
@@ -0,0 +1,77 @@
+import { describe, expect, it } from "vitest";
+import {
+	DEFAULT_WORKSPACE_ID,
+	isValidSlug,
+	parsePath,
+	WORKSPACE_SLUG_RE,
+	workspacePath,
+} from "./route";
+
+describe("parsePath", () => {
+	it("treats the root path as home", () => {
+		expect(parsePath("/")).toEqual({ kind: "home" });
+		expect(parsePath("")).toEqual({ kind: "home" });
+	});
+
+	it("trims surrounding slashes", () => {
+		expect(parsePath("//")).toEqual({ kind: "home" });
+		expect(parsePath("/my-ws/")).toEqual({ kind: "workspace", id: "my-ws" });
+	});
+
+	it("parses a single segment as a workspace id", () => {
+		expect(parsePath("/default")).toEqual({ kind: "workspace", id: "default" });
+		expect(parsePath("/my-workspace")).toEqual({ kind: "workspace", id: "my-workspace" });
+		expect(parsePath("/ws1")).toEqual({ kind: "workspace", id: "ws1" });
+	});
+
+	it("takes only the first segment of a deeper path", () => {
+		expect(parsePath("/foo/bar")).toEqual({ kind: "workspace", id: "foo" });
+		expect(parsePath("/foo/bar/baz")).toEqual({ kind: "workspace", id: "foo" });
+	});
+
+	it("URL-decodes the segment", () => {
+		expect(parsePath("/my%20ws")).toEqual({ kind: "workspace", id: "my ws" });
+	});
+
+	it("does not validate the slug — an invalid id is still a workspace route", () => {
+		expect(parsePath("/UPPER")).toEqual({ kind: "workspace", id: "UPPER" });
+		expect(parsePath("/has space")).toEqual({ kind: "workspace", id: "has space" });
+	});
+});
+
+describe("isValidSlug", () => {
+	it("accepts lowercase alphanumeric + internal hyphens", () => {
+		expect(isValidSlug("default")).toBe(true);
+		expect(isValidSlug("my-workspace")).toBe(true);
+		expect(isValidSlug("a")).toBe(true);
+		expect(isValidSlug("ws-1")).toBe(true);
+	});
+
+	it("accepts up to 40 chars", () => {
+		expect(isValidSlug("a".repeat(40))).toBe(true);
+	});
+
+	it("rejects empty and too-long", () => {
+		expect(isValidSlug("")).toBe(false);
+		expect(isValidSlug("a".repeat(41))).toBe(false);
+	});
+
+	it("rejects uppercase, spaces, and leading/trailing hyphens", () => {
+		expect(isValidSlug("MyWS")).toBe(false);
+		expect(isValidSlug("has space")).toBe(false);
+		expect(isValidSlug("-leading")).toBe(false);
+		expect(isValidSlug("trailing-")).toBe(false);
+		expect(isValidSlug("double--hyphen")).toBe(true); // internal doubles are allowed by the regex
+	});
+
+	it("WORKSPACE_SLUG_RE matches the default id", () => {
+		expect(WORKSPACE_SLUG_RE.test(DEFAULT_WORKSPACE_ID)).toBe(true);
+	});
+});
+
+describe("workspacePath", () => {
+	it("builds the URL path for a workspace id", () => {
+		expect(workspacePath("default")).toBe("/default");
+		expect(workspacePath("my-ws")).toBe("/my-ws");
+	});
+});