Fix sidebar content overflow and set correct window taskbar icon

The sidebar config panel content was overflowing its container width,
causing project names and directory paths to be clipped. Added min-w-0
and overflow-hidden to flex containers, and restructured folder path
config rows to stack vertically instead of cramming into one line.

The Windows taskbar was showing a black square because no default window
icon was set at runtime. Added default_window_icon() call in the Tauri
builder using the app's icon.png.

Also adds vitest test infrastructure with tests verifying both fixes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/components/projects/ProjectCard.test.tsx

@@ -0,0 +1,128 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent, act } from "@testing-library/react";
+import ProjectCard from "./ProjectCard";
+import type { Project } from "../../lib/types";
+
+// Mock Tauri dialog plugin
+vi.mock("@tauri-apps/plugin-dialog", () => ({
+  open: vi.fn(),
+}));
+
+// Mock hooks
+const mockUpdate = vi.fn();
+const mockStart = vi.fn();
+const mockStop = vi.fn();
+const mockRebuild = vi.fn();
+const mockRemove = vi.fn();
+
+vi.mock("../../hooks/useProjects", () => ({
+  useProjects: () => ({
+    start: mockStart,
+    stop: mockStop,
+    rebuild: mockRebuild,
+    remove: mockRemove,
+    update: mockUpdate,
+  }),
+}));
+
+vi.mock("../../hooks/useTerminal", () => ({
+  useTerminal: () => ({
+    open: vi.fn(),
+  }),
+}));
+
+let mockSelectedProjectId: string | null = null;
+vi.mock("../../store/appState", () => ({
+  useAppState: vi.fn((selector) =>
+    selector({
+      selectedProjectId: mockSelectedProjectId,
+      setSelectedProject: vi.fn(),
+    })
+  ),
+}));
+
+const mockProject: Project = {
+  id: "test-1",
+  name: "Test Project",
+  paths: [{ host_path: "/home/user/project", mount_name: "project" }],
+  container_id: null,
+  status: "stopped",
+  auth_mode: "login",
+  bedrock_config: null,
+  allow_docker_access: false,
+  ssh_key_path: null,
+  git_token: null,
+  git_user_name: null,
+  git_user_email: null,
+  custom_env_vars: [],
+  claude_instructions: null,
+  created_at: "2026-01-01T00:00:00Z",
+  updated_at: "2026-01-01T00:00:00Z",
+};
+
+describe("ProjectCard", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockSelectedProjectId = null;
+  });
+
+  it("renders project name and path", () => {
+    render(<ProjectCard project={mockProject} />);
+    expect(screen.getByText("Test Project")).toBeInTheDocument();
+    expect(screen.getByText("/workspace/project")).toBeInTheDocument();
+  });
+
+  it("card root has min-w-0 and overflow-hidden to contain content", () => {
+    const { container } = render(<ProjectCard project={mockProject} />);
+    const card = container.firstElementChild;
+    expect(card).not.toBeNull();
+    expect(card!.className).toContain("min-w-0");
+    expect(card!.className).toContain("overflow-hidden");
+  });
+
+  describe("when selected and showing config", () => {
+    beforeEach(() => {
+      mockSelectedProjectId = "test-1";
+    });
+
+    it("expanded area has min-w-0 and overflow-hidden", () => {
+      const { container } = render(<ProjectCard project={mockProject} />);
+      // The expanded section (mt-2 ml-4) contains the auth/action/config controls
+      const expandedSection = container.querySelector(".ml-4.mt-2");
+      expect(expandedSection).not.toBeNull();
+      expect(expandedSection!.className).toContain("min-w-0");
+      expect(expandedSection!.className).toContain("overflow-hidden");
+    });
+
+    it("folder path inputs use min-w-0 to allow shrinking", async () => {
+      const { container } = render(<ProjectCard project={mockProject} />);
+
+      // Click Config button to show config panel
+      await act(async () => {
+        fireEvent.click(screen.getByText("Config"));
+      });
+
+      // After config is shown, check the folder host_path input has min-w-0
+      const hostPathInputs = container.querySelectorAll('input[placeholder="/path/to/folder"]');
+      expect(hostPathInputs.length).toBeGreaterThan(0);
+      expect(hostPathInputs[0].className).toContain("min-w-0");
+    });
+
+    it("config panel container has overflow-hidden", async () => {
+      const { container } = render(<ProjectCard project={mockProject} />);
+
+      // Click Config button
+      await act(async () => {
+        fireEvent.click(screen.getByText("Config"));
+      });
+
+      // The config panel has border-t and overflow containment classes
+      const allDivs = container.querySelectorAll("div");
+      const configPanel = Array.from(allDivs).find(
+        (div) => div.className.includes("border-t") && div.className.includes("min-w-0")
+      );
+      expect(configPanel).toBeDefined();
+      expect(configPanel!.className).toContain("overflow-hidden");
+    });
+  });
+});