Build MVP: campaigns, characters, combat, dice, compendium

- Rules abstraction (5e + pf2e) behind one interface, fully tested
- Pure combat engine: turn-order safe across add/remove/reorder/init-change
- Dexie storage with real cascade deletes + Zod validation on write
- Seedable dice engine with notation parser
- Lazy SRD compendium (code-split), bestiary -> combat
- Strict TS, 54 unit tests, Playwright e2e smoke (all green)

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

vitest.config.ts

@@ -0,0 +1,17 @@
+import { defineConfig } from 'vitest/config';
+import { fileURLToPath, URL } from 'node:url';
+
+export default defineConfig({
+  resolve: {
+    alias: {
+      '@': fileURLToPath(new URL('./src', import.meta.url)),
+    },
+  },
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    setupFiles: ['./vitest.setup.ts'],
+    css: false,
+    exclude: ['**/node_modules/**', '**/e2e/**', '**/dist/**'],
+  },
+});