feat: implement Q&A database persistence and Telegram bot integration

backend/src/main/java/com/rit/portal/entity/CommunityAnswer.java

@@ -0,0 +1,40 @@
+package com.rit.portal.entity;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import jakarta.persistence.*;
+import lombok.*;
+import java.time.LocalDateTime;
+
+@Entity
+@Table(name = "community_answers")
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+public class CommunityAnswer {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Integer id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "question_id", nullable = false)
+    @JsonIgnore
+    private CommunityQuestion question;
+
+    @Column(nullable = false, columnDefinition = "TEXT")
+    private String body;
+
+    @Column(nullable = false)
+    private String author;
+
+    @Column(name = "upvotes")
+    private Integer upvotes = 0;
+
+    @Column(name = "is_accepted")
+    private Boolean isAccepted = false;
+
+    @Column(name = "created_at")
+    private LocalDateTime createdAt = LocalDateTime.now();
+}

backend/src/main/java/com/rit/portal/entity/CommunityQuestion.java

@@ -0,0 +1,46 @@
+package com.rit.portal.entity;
+
+import jakarta.persistence.*;
+import lombok.*;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+@Entity
+@Table(name = "community_questions")
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+public class CommunityQuestion {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Integer id;
+
+    @Column(nullable = false)
+    private String title;
+
+    @Column(nullable = false, columnDefinition = "TEXT")
+    private String body;
+
+    @Column(nullable = false)
+    private String author;
+
+    @Column(name = "upvotes")
+    private Integer upvotes = 0;
+
+    @Column(name = "tags", columnDefinition = "text[]")
+    private List<String> tags = new ArrayList<>();
+
+    @Column(name = "is_answered")
+    private Boolean isAnswered = false;
+
+    @Column(name = "created_at")
+    private LocalDateTime createdAt = LocalDateTime.now();
+
+    @OneToMany(mappedBy = "question", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
+    @Builder.Default
+    private List<CommunityAnswer> answers = new ArrayList<>();
+}

backend/src/main/java/com/rit/portal/entity/NotePyq.java

@@ -15,7 +15,7 @@ public class NotePyq {
 
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
-    private Long id;
+    private Integer id;
 
     @Column(nullable = false)
     private String title;