chore: rename project to excalidraw-mcp-sentinel
- Package name: @sanjibdevnath/mcp-excalidraw-local → excalidraw-mcp-sentinel
- GitHub repo: celstnblacc/mcp-excalidraw-local → celstnblacc/excalidraw-mcp-sentinel
- Docker images, CLI binary, CI workflows, docs all updated
- Version reset to 1.0.0 for independent release track
- Added "Why this fork?" section to README
- Removed superseded planning docs (PLAN.md, PLAN_v2.md, REVIEW.md, HANDOFF.md)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>