Phase 11: data-driven Assistant

- Deterministic advisors (src/lib/assistant): party resources (downed/bloodied/
  spent slots/rest nudges), session prep (dangling [[wiki links]], active quests,
  empty journal), live combat hints (turn, downed combatants) — pure + tested
- Data-driven encounter builder: greedily assembles level/CR-appropriate monsters
  to a target difficulty via the Phase-3 budget; one click builds + opens combat
- Assistant page: suggestion cards with one-click actions (goto, long rest,
  create note); wired into routes, dashboard, command palette
- 8 advisor/builder unit tests + assistant e2e

Conversational LLM layer intentionally deferred (no provider/key in this env);
the deterministic advisor is the offline default per the plan.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/components/CommandPalette.tsx

@@ -17,6 +17,7 @@ interface Command {
 const NAV: { label: string; to: string }[] = [
   { label: 'Campaigns', to: '/' },
   { label: 'Dashboard', to: '/dashboard' },
+  { label: 'Assistant', to: '/assistant' },
   { label: 'Characters', to: '/characters' },
   { label: 'Combat', to: '/combat' },
   { label: 'Dice', to: '/dice' },