Adds two new MCP tools for working with free-form text annotations
(SCH_TEXT elements) in KiCad schematics:
- add_schematic_text: place a text note with optional angle, font size,
bold/italic, and justification
- list_schematic_texts: list all text annotations with optional
case-insensitive substring filter
Includes WireManager.add_text / list_texts using _text_insert + sexpdata,
handler dispatch in KiCADInterface, TypeScript tool definitions, registry
entry, reference doc updates, and 30 unit tests.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>