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/cli/package.json

@@ -0,0 +1,44 @@
+{
+  "name": "@modelcontextprotocol/inspector-cli",
+  "version": "2.0.0",
+  "private": true,
+  "description": "CLI for the Model Context Protocol inspector",
+  "license": "MIT",
+  "type": "module",
+  "main": "build/index.js",
+  "exports": {
+    ".": "./build/index.js"
+  },
+  "bin": {
+    "mcp-inspector-cli": "./build/index.js"
+  },
+  "files": [
+    "build"
+  ],
+  "scripts": {
+    "build": "tsup",
+    "pretest": "npm run test-servers:build && npm run build",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test-servers:build": "tsc -p ../../test-servers --noCheck",
+    "test:cli": "vitest run cli.test.ts",
+    "test:cli-tools": "vitest run tools.test.ts",
+    "test:cli-headers": "vitest run headers.test.ts",
+    "test:cli-metadata": "vitest run metadata.test.ts"
+  },
+  "dependencies": {
+    "@modelcontextprotocol/sdk": "^1.29.0",
+    "ajv": "^8.17.1",
+    "atomically": "^2.1.1",
+    "commander": "^13.1.0",
+    "pino": "^9.14.0",
+    "zod": "^4.3.6",
+    "zustand": "^5.0.13"
+  },
+  "devDependencies": {
+    "@types/node": "^24.12.4",
+    "tsup": "^8.5.0",
+    "typescript": "~5.9.3",
+    "vitest": "^4.1.0"
+  }
+}