feat: post-prestige automation (auto-adventurer) (#76)

## Summary

Closes #61

- Adds the **Autonomous Recruitment** prestige upgrade (50 runestones) to both the API and web data files
- Adds `autoAdventurer?: boolean` to the `GameState` type for backwards-compatible saves
- Adds tick-loop logic in GameContext that automatically purchases the highest-tier unlocked adventurer the player can afford each frame when the toggle is enabled
- Adds `toggleAutoAdventurer` callback and exposes it through the context
- Adds toggle UI in the Prestige Shop (mirrors the existing Auto-Prestige toggle pattern)
- Updates the How to Play guide in the About panel to document the new automation feature

✨ This issue was created with help from Hikari~ 🌸

Reviewed-on: #76
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

packages/types/src/interfaces/gameState.ts

@@ -79,6 +79,11 @@ interface GameState {
    */
   autoBoss?: boolean;
 
+  /**
+   * When true, the tick engine automatically purchases the highest-tier affordable adventurer.
+   */
+  autoAdventurer?: boolean;
+
   /**
    * Companion unlock and active selection state — optional for backwards compatibility.
    */