chore: Add MCPB packaging files for cross-platform Claude Desktop bundle

[bryan-anthropic]

Summary

Adds MCPB packaging files to enable building a cross-platform .mcpb bundle for the Claude Desktop MCP Directory. No existing code is modified — this PR only adds packaging metadata.

File	Size	Purpose
manifest.json	~40 KB	MCPB v0.4 manifest — 265 tools, user config, compatibility, privacy policy
.mcpbignore	~300 B	Excludes non-runtime files from the bundle
icon.png	~23 KB	Zscaler cloud icon for the MCP Directory listing

Why server.type: "uv" instead of server.type: "python"?

Python MCP servers that bundle dependencies via pip install --target embed platform-specific compiled extensions (.so/.pyd files from packages like pydantic-core, cryptography, orjson). These binaries are locked to the OS and CPU architecture where the bundle was built.

The uv-native approach (server.type: "uv") solves this by deferring dependency resolution to runtime. When a user installs the bundle, uv reads pyproject.toml, resolves the correct platform-specific wheels for their system, and caches them locally.

	pip --target bundle	uv-native bundle
Bundle size	~58 MB	~222 KB
Cross-platform	No (platform-locked .so files)	Yes
macOS (Intel + ARM)	Only if built on matching arch	Works
Windows	Only if built on Windows	Works
Linux	Only if built on Linux	Works

How it works

The manifest declares server.type: "uv" with this config:

{
  "command": "uv",
  "args": ["run", "python", "-m", "zscaler_mcp.server"],
  "env": {
    "PYTHONPATH": "${__dirname}",
    ...
  }
}

At runtime, uv run reads pyproject.toml, resolves dependencies into a cached virtual environment with platform-correct wheels, then executes the server. The bundle only needs to contain source code + pyproject.toml — no pre-compiled binaries.

Building the bundle

npx @anthropic-ai/mcpb@latest pack

This produces a zscaler-mcp-server-0.6.2.mcpb file (~222 KB) containing the source code, pyproject.toml, manifest, icon, license, and README.

What's in the manifest

• 265 tools across 10 services (ZIA, ZPA, ZDX, ZCC, ZTW, ZIdentity, EASM, Z-Insights, plus 2 core utilities)
• 11 user-configurable fields (authentication, service selection, write-mode controls)
• Privacy policy: https://www.zscaler.com/privacy-policy
• Compatibility: macOS, Windows, Linux — Python >=3.11

Test plan

• npx @anthropic-ai/mcpb@latest pack succeeds from repo root
• Bundle size is ~222 KB (not ~58 MB)
• Extracted bundle contains no .so, .pyd, or __pycache__ files
• Bundle contains pyproject.toml (required for uv dependency resolution)
• Install in Claude Desktop — server starts and reports 265 tools