Inspector sidebar with note insights

New

• The new Inspector sidebar gives every note a compact on-device generated summary, writing stats with task progress, a navigable outline, and related notes from your library. Open it with ⌥⌘I or from the View menu.
• AI chat is now a standard feature — always one ⇧⌘J away from any note, no longer hidden behind an experimental toggle.

Fixed

• Clicking the preview tip now toggles preview mode as expected.
• The outline popover header now consistently reads "Outline".