fix: Replace git+https:// install source with archive (zip) or tagged releases to avoid Git dependency

[dem108]

Summary

On Windows (and some managed environments), uvx fails when resolving VCS sources because it shells out to a git executable that may not exist in the inherited PATH. Using a GitHub archive URL (or a tagged release) removes the runtime Git dependency and works reliably with uvx.

Motivation

• Fixes “Git executable not found” when launching the MCP server from clients like Claude Desktop.
• Improves first-run success rate and onboarding (esp. Windows).
• More reproducible and cacheable installs; easier to pin to tags.
• Aligns with ecosystem guidance: VCS URLs for dev/contributors; archives/tags for users.

Proposal

• Replace --from git+https://github...@branch/commit with --from https://github.com/azure-ai-foundry/mcp-foundry/archive/refs/tags/vX.Y.Z.zip (preferred) or refs/heads/main.zip (if no tags yet).
• Document a fallback strategy (prefer tag; otherwise archive; VCS only for contributors).

Acceptance Criteria

• Launch instructions work on Windows without Git installed.
• CI smoke test covering uvx --from passes on Windows/Linux/macOS.
• Docs updated (README, examples, client snippets).