Make the MCP server work well in real chat clients #89

Trying the MCP server from real chat clients turned up schema bugs and a few missing pieces. Fixed and added on 6 November:

• Write null fields so tool results match their output schemas: Write null fields so tool results match their output schemas CleanModelContextProtocol#49
• Write nullable schema fields as anyOf so single-type clients accept them: Write nullable tool schema fields as anyOf so single-type clients accept them CleanModelContextProtocol#50
• Link each movie, author and review a tool returns to its resource: Link each movie, author and review a tool returns to its resource CleanModelContextProtocol#51
• Optional chat demo with Open WebUI behind a compose profile: Add an optional chat demo with Open WebUI behind a compose profile CleanModelContextProtocol#52
• Autocomplete resource template ids and give every item an icon: Autocomplete resource template ids and give every item an icon CleanModelContextProtocol#53, icons in Add a small MCP icon set for tools, prompts and resources brand#13
• Browsable top rated movies resource: Add a browsable top rated movies resource CleanModelContextProtocol#54
• Prompts that summarise an author's reviews and a movie's reviews: Add a prompt that summarises an author's reviews CleanModelContextProtocol#55, Add a prompt that summarises what a movie's reviews say CleanModelContextProtocol#58
• Docs: Bring the docs up to date with review text, review search and the new MCP features leanmeancleanapps.github.io#21

Filed after the work merged, so the board shows it in the 1 December release.