feat: add rename_page and get_page_backlinks tools

[lfnovo]

Summary

This PR adds four new MCP tools for enhanced page and namespace management:

Namespace Tools

• get_pages_from_namespace - Get all pages within a specific namespace

  • Returns flat list of pages matching the namespace prefix
  • Uses logseq.Editor.getPagesFromNamespace API

• get_pages_tree_from_namespace - Get hierarchical tree of pages in a namespace

  • Returns nested structure showing parent-child relationships
  • Uses logseq.Editor.getPagesTreeFromNamespace API

Page Utility Tools

• rename_page - Rename a page and automatically update all references throughout the graph

  • Pre-validates that source page exists and target name is available
  • Uses logseq.Editor.renamePage API

• get_page_backlinks - Retrieve all pages and blocks that reference a specific page

  • Groups results by referencing page with reference counts
  • Optional include_content parameter to include/exclude block details
  • Uses logseq.Editor.getPageLinkedReferences API

Changes

• Added 4 new API methods to logseq.py
• Added 4 new tool handlers to tools.py
• Registered handlers in server.py
• Added comprehensive unit tests (77 total tests pass)
• Total tools: 10 (up from 6)

Test plan

• All 77 unit tests pass (uv run pytest)
• Integration test verifies 10 tools registered
• Manual testing with real LogSeq instance