feat: economy system with minigames, bank, rob, jobs, fishing, blackjack, slots

+ economy domain (EconomyAccount, Job, SlotCombination, EconomyTransaction)
+ EconomyRepository + SqlEconomyRepository + DB schema
+ EconomyService (transfer, daily, deposit/withdraw, stat upgrades)
+ FishingService (fish grid with difficulty levels, speed bonus)
+ BlackjackService (dealer stands on 16, ties lose)
+ SlotService (weighted combos up to x50)
+ JobService (6 jobs with level reqs and efficiency stat)
+ 11 commands: balance, baltop, pay, daily, bank, rob,
  fish, blackjack, slot, job, work
+ Tests for SqlEconomyRepository
+ EconomyModule + EconomyCommandRegistrar wired into BotModule

.github/workflows/ci.yml

@@ -0,0 +1,19 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          java-version: "21"
+          distribution: "temurin"
+      - uses: gradle/actions/setup-gradle@v4
+      - run: ./gradlew build