feat: add personajes page with level tracking and fix timer reactivity

- New /personajes page with CRUD for characters (name, class, level)
- Level editable inline, deletable (blocked if has active sales)
- ventas.html now loads characters list as datalist suggestions
- Fix timer: add reactive 'now' property so countdown updates
- Fix script loading: add defaults.js + app.js to ventas/personajes
- Fix table auto-reload: use loadCharacters()/loadSales() after mutations
- Timer now uses setTimeout recursion + visibilitychange handler

src/main/java/com/l2/shots/characters/Character.java

@@ -0,0 +1,36 @@
+package com.l2.shots.characters;
+
+import io.quarkus.hibernate.orm.panache.PanacheEntityBase;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+import java.util.UUID;
+
+@Entity
+@Table(name = "characters", indexes = {
+        @Index(name = "idx_characters_user", columnList = "user_id")
+})
+public class Character extends PanacheEntityBase {
+
+    @Id
+    public UUID id;
+
+    @Column(name = "user_id", nullable = false)
+    public UUID userId;
+
+    @Column(name = "name", nullable = false, length = 50)
+    public String name;
+
+    @Column(name = "character_class", nullable = false, length = 30)
+    public String characterClass;
+
+    @Column(name = "level", nullable = false)
+    public int level;
+
+    @Column(name = "created_at", nullable = false)
+    public Instant createdAt;
+}