feat: communicate quest failure mechanics in the UI (#82)

## Summary

Addresses recurring community confusion about quests failing — multiple players asked whether it was a bug or intended behaviour with no in-game explanation.

- **Exports `zoneFailureChance`** from `tick.ts` so the quest panel can read it
- **Quest cards** now show a `🎲 X% failure chance` note on all available quests, with a brief explanation that a failure resets the quest with no rewards
- **"Last attempt failed" hint** now reads `"⚠️ Last attempt failed — no rewards were granted."` so players understand the consequence immediately
- **About panel** updated to document the failure mechanic, including the 10%–40% range across zones

Closes #80

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #82
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/web/src/components/game/questPanel.tsx

@@ -10,6 +10,7 @@
 /* eslint-disable max-statements -- Many local variables needed for quest state */
 import { useState, type JSX } from "react";
 import { useGame } from "../../context/gameContext.js";
+import { zoneFailureChance } from "../../engine/tick.js";
 import { cdnImage } from "../../utils/cdn.js";
 import { LockToggle } from "../ui/lockToggle.js";
 import { ZoneSelector } from "./zoneSelector.js";
@@ -143,8 +144,18 @@ const QuestCard = ({
               : null}
           </>
         }
+        {quest.status === "available"
+          && <p className="quest-failure-chance">
+            {"🎲 "}
+            {String(Math.round((zoneFailureChance[quest.zoneId] ?? 0) * 100))}
+            {"% failure chance — if failed, the quest resets"}
+            {" and must be retried."}
+          </p>
+        }
         {quest.status === "available" && quest.lastFailedAt !== undefined
-          && <p className="quest-failed-hint">{"⚠️ Last attempt failed"}</p>
+          && <p className="quest-failed-hint">
+            {"⚠️ Last attempt failed — no rewards were granted."}
+          </p>
         }
         {quest.status === "available"
           && <button