feat: port CLI, TUI, and launcher from v1.5 into v2 (#1452)

Ports the CLI, TUI, and launcher from v1.5 into v2 behind a single
`mcp-inspector` entrypoint (launcher → web/cli/tui). Includes the
`mcp-inspector --web --dev` launcher fix (Vite alias resolution + prod-server
double-start), the root `postinstall` install cascade with simplified CI, and
spec/AGENTS docs (no-workspaces rationale, Development setup).

Closes #1246.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/tui/__tests__/tui.test.ts

@@ -0,0 +1,21 @@
+import { describe, it, expect } from "vitest";
+import { tabs } from "../src/components/tabsConfig.js";
+
+describe("TUI", () => {
+  it("exports tabs with expected shape", () => {
+    expect(Array.isArray(tabs)).toBe(true);
+    expect(tabs.length).toBeGreaterThan(0);
+    for (const tab of tabs) {
+      expect(tab).toHaveProperty("id");
+      expect(tab).toHaveProperty("label");
+      expect(tab).toHaveProperty("accelerator");
+    }
+  });
+
+  it("includes info tab", () => {
+    const info = tabs.find((t) => t.id === "info");
+    expect(info).toBeDefined();
+    expect(info?.label).toBe("Info");
+    expect(info?.accelerator).toBe("i");
+  });
+});