Implements the highest-leverage items from docs/grammarly-value-plan.md:
- Live Check: on-device 0-100 writing score, Correctness/Clarity/Polish
count chips, and per-suggestion Dismiss / Add-to-dictionary (a cheap,
always-available 'no' is what makes 'Apply' feel safe).
- Value loop: day-streak, correction milestones and a 'subscription you
didn't pay' figure on the dashboard + a streak line in the menu bar
(all local, self-vs-self, no telemetry).
- First-run demo: a planted sample the real engine cleans in one click,
before any permission ask.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
