feat(jpa): add JPA entities and repositories aligned to Flyway; chore(deps): remove unused AMQP deps

src/main/java/com/mosquito/project/persistence/entity/ActivityEntity.java

@@ -0,0 +1,62 @@
+package com.mosquito.project.persistence.entity;
+
+import jakarta.persistence.*;
+import java.time.OffsetDateTime;
+
+@Entity
+@Table(name = "activities")
+public class ActivityEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(nullable = false, length = 255)
+    private String name;
+
+    @Column(name = "start_time_utc", nullable = false)
+    private OffsetDateTime startTimeUtc;
+
+    @Column(name = "end_time_utc", nullable = false)
+    private OffsetDateTime endTimeUtc;
+
+    @Column(name = "target_users_config", columnDefinition = "jsonb")
+    private String targetUsersConfig;
+
+    @Column(name = "page_content_config", columnDefinition = "jsonb")
+    private String pageContentConfig;
+
+    @Column(name = "reward_calculation_mode", length = 50)
+    private String rewardCalculationMode;
+
+    @Column(length = 50)
+    private String status;
+
+    @Column(name = "created_at")
+    private OffsetDateTime createdAt;
+
+    @Column(name = "updated_at")
+    private OffsetDateTime updatedAt;
+
+    public Long getId() { return id; }
+    public void setId(Long id) { this.id = id; }
+    public String getName() { return name; }
+    public void setName(String name) { this.name = name; }
+    public OffsetDateTime getStartTimeUtc() { return startTimeUtc; }
+    public void setStartTimeUtc(OffsetDateTime startTimeUtc) { this.startTimeUtc = startTimeUtc; }
+    public OffsetDateTime getEndTimeUtc() { return endTimeUtc; }
+    public void setEndTimeUtc(OffsetDateTime endTimeUtc) { this.endTimeUtc = endTimeUtc; }
+    public String getTargetUsersConfig() { return targetUsersConfig; }
+    public void setTargetUsersConfig(String targetUsersConfig) { this.targetUsersConfig = targetUsersConfig; }
+    public String getPageContentConfig() { return pageContentConfig; }
+    public void setPageContentConfig(String pageContentConfig) { this.pageContentConfig = pageContentConfig; }
+    public String getRewardCalculationMode() { return rewardCalculationMode; }
+    public void setRewardCalculationMode(String rewardCalculationMode) { this.rewardCalculationMode = rewardCalculationMode; }
+    public String getStatus() { return status; }
+    public void setStatus(String status) { this.status = status; }
+    public OffsetDateTime getCreatedAt() { return createdAt; }
+    public void setCreatedAt(OffsetDateTime createdAt) { this.createdAt = createdAt; }
+    public OffsetDateTime getUpdatedAt() { return updatedAt; }
+    public void setUpdatedAt(OffsetDateTime updatedAt) { this.updatedAt = updatedAt; }
+}
+