feat: shot-crafter-calculator with H2 persistence and production history

Quarkus 3.20.1 monolith serving React 18 + TypeScript + Tailwind SPA.

Features:
- Three-tab calculator (Insumos, Fórmulas, Calculadora) for
  Soulshot, Spiritshot and Blessed Spiritshot crafting in Lineage 2
  Interlude/Clásico with all 15 grades and pre-loaded recipes
- Real-time profitability computation (cristales → ore →
  crafteos → shots → cost → sale → ganancia)
- Multi-user auth with JWT in httpOnly cookie (bcrypt + RSA 2048)
- H2 file-based persistence in ./data/shots.mv.db (file-based, H2)
- Auto-save on state changes (debounced 500ms)
- Production history with stats (total/avg/best/worst/last5avg)
  and per-run detail modal with snapshot of insumos+formulas

Stack:
- Backend: Quarkus REST + Hibernate ORM Panache + smallrye-jwt
- Frontend: React 18 + TypeScript + Vite + Tailwind 3
- Build: Maven runs frontend-maven-plugin (Node 22 + npm ci)
  then copies dist to META-INF/resources for Quarkus to serve

Verified:
- 5 backend endpoints + 5 history endpoints with curl
- 35/35 browser tests via Playwright + Chromium
- All TS strict, all builds green

src/main/java/com/l2/shots/auth/Credentials.java

@@ -0,0 +1,6 @@
+package com.l2.shots.auth;
+
+public class Credentials {
+    public String username;
+    public String password;
+}