Add Inflytande resource, expand events, and balance the endgame

Adds an influence currency that scales with follower count and a new
"exert influence" action to trade it for secrecy, uncaps recruiting
with scaling cost, adds a late-game Andakt sink, and makes hemlighet
drain scale with dread/ritual progress so the endgame carries real
risk. Includes a Vitest suite that simulates play to check balance,
which caught the influence-accrual rate being too slow to be useful
early game.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

package.json

@@ -6,10 +6,12 @@
     "dev": "vite --port 5681",
     "build": "vite build",
     "typecheck": "tsc",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run"
   },
   "devDependencies": {
     "typescript": "^5.5.0",
-    "vite": "^6.0.0"
+    "vite": "^6.0.0",
+    "vitest": "^4.1.10"
   }
 }