Update docs and surface for SDK v0.7.0 commands

- API-COVERAGE.md: add gauges, my_assignments, my_notifications, account
  sections; update summary (42 sections, 155 endpoints) and SDK version
- SKILL.md: add triggers, quick reference rows, decision tree entries,
  and resource reference sections for all four new command groups;
  update endpoint count (130 → 155) and cross-project exception list
- .surface: regenerated snapshot (148 commands, 422 flags)

Author: jeremy