The MCP 2025-11-25 specification defines an optional `title` property on
Prompt for human-readable display in UI contexts, distinct from the
programmatic `name` identifier. This was missing from the SDK.
BC Break: Builder::addPrompt() signature changed — $title parameter added
between $name and $description. Callers using positional arguments for
$description must switch to named arguments.
Closes#276
7af5a345c1