docs: add calendar participants and participant save fix to 1.6.7 changelog

Merge pull request #544 from OpenWhispr/meeting-participants

fix(notes): broadcast calendar attendees to store and stabilize participant saves

fix(notes): prevent participants from leaking across notes

feat(notes): add calendar participants and note linking

Merge pull request #543 from xAlcahest/chore/bump-xmldom-0.8.12

revert: undo macOS titlebar spacing experiments

fix(ui): extend sidebar chat panel to top of window on macOS

fix(ui): align macOS content area with sidebar traffic lights

chore(deps): bump @xmldom/xmldom from 0.8.11 to 0.8.12

fix(ui): center macOS traffic lights with sidebar search bar

fix(ui): remove macOS drag bar from content area to eliminate dead space

fix(ui): reduce macOS title bar dead space to align content with traffic lights

feat(chat): note-scoped conversations with per-note chat history

perf(build): strip non-target onnxruntime-node binaries in afterPack