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>

.claude/launch.json

@@ -0,0 +1,11 @@
+{
+  "version": "0.0.1",
+  "configurations": [
+    {
+      "name": "dev",
+      "runtimeExecutable": "bun",
+      "runtimeArgs": ["run", "dev"],
+      "port": 5173
+    }
+  ]
+}