New project_memory_list and project_memory_read tool methods

What

Two new methods are added alongside the existing project_info/project_read/project_search:

• project_memory_list lists a project's memory files (path, size in bytes, last-updated time, and whether the list was truncated), capped at a fixed number of entries with a truncation notice when there are more.
• project_memory_read reads a single memory file by path, returning its content (with a truncation notice if the server had to cut the file short).

Both methods have matching UI action descriptions ("List project memory", "Read project memory file") and are backed by a real tool that reads documents from the memory store.

Why

This gives Claude Code a way to browse and read a project's stored memory files directly, rather than only being able to access general project info, files, or search.