v0.8.1 - listed where clients look

Gets OSWright listed in the official MCP registry, which is how MCP clients
discover servers.

The registry proves that the same person controls both the GitHub repository
and the PyPI package by looking for an mcp-name: marker in the README that
ships inside the package. That marker only reaches PyPI on a release, so this
is one.

• Badges for PyPI version, CI status, Python versions and licence.
• POST.md rewritten. It was a draft from v0.3 pitching "every action returns a
  fresh screenshot so the agent always has context" -- precisely the design the
  last eight versions replaced. A launch post that contradicts its own project
  is worse than none.

No functional changes to the library. See v0.8.0 for the perception work and
the measurements.