docs: align python mcp first-user path

[heznpc]

Summary

• Aligns the repo with the current starter-series first-user path and unscoped package naming contract.
• Keeps agent-facing adapters thin so Codex, Claude, Cursor, VS Code/Copilot, and similar shell-driven tools read the same repo-local source of truth.
• Tightens repo-local verification where the touched surface affects install, package, CI, or release behavior.

Verification

• Repo-local lint/test/build/package gates were run before commit where applicable.
• Staged whitespace checks passed before commit.
• CI on this PR is the merge gate.