feat(api): implement exam and grade synchronization modules

Add new functionality for managing and synchronizing academic grades and exam schedules. This includes new models, repositories, services, and HTTP handlers, along with updated gRPC definitions and dependency injection configuration.

Additionally, improve the reliability of unread message count tracking by implementing an atomic Lua script for Redis operations in the conversation cache.

internal/model/grade.go

@@ -0,0 +1,51 @@
+package model
+
+import (
+	"time"
+
+	"gorm.io/gorm"
+)
+
+type Grade struct {
+	ID         string `json:"id" gorm:"type:varchar(36);primaryKey"`
+	UserID     string `json:"user_id" gorm:"type:varchar(36);index;not null"`
+	Term       string `json:"term" gorm:"type:varchar(30);not null"`
+	CourseCode string `json:"course_code" gorm:"type:varchar(30)"`
+	CourseName string `json:"course_name" gorm:"type:varchar(120);not null"`
+	Nature     string `json:"nature" gorm:"type:varchar(30)"`
+	Category   string `json:"category" gorm:"type:varchar(30)"`
+	Credit     string `json:"credit" gorm:"type:varchar(10)"`
+	Score      string `json:"score" gorm:"type:varchar(20)"`
+	GradePoint string `json:"grade_point" gorm:"type:varchar(10)"`
+	IsExam     string `json:"is_exam" gorm:"type:varchar(10)"`
+	CreatedAt  time.Time
+	UpdatedAt  time.Time
+}
+
+func (g *Grade) BeforeCreate(tx *gorm.DB) error {
+	SetUUIDIfEmpty(&g.ID)
+	return nil
+}
+
+func (Grade) TableName() string { return "grades" }
+
+type GpaSummary struct {
+	ID              string `json:"id" gorm:"type:varchar(36);primaryKey"`
+	UserID          string `json:"user_id" gorm:"type:varchar(36);index;not null"`
+	Semester        string `json:"semester" gorm:"type:varchar(30);not null"`
+	AverageGpa      string `json:"average_gpa" gorm:"type:varchar(20)"`
+	Rank            string `json:"rank" gorm:"type:varchar(30)"`
+	ExamTotalGpa    string `json:"exam_total_gpa" gorm:"type:varchar(20)"`
+	ExamTotalCredits string `json:"exam_total_credits" gorm:"type:varchar(20)"`
+	FailCredits     string `json:"fail_credits" gorm:"type:varchar(20)"`
+	Semesters       string `json:"semesters" gorm:"type:varchar(20)"`
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+}
+
+func (g *GpaSummary) BeforeCreate(tx *gorm.DB) error {
+	SetUUIDIfEmpty(&g.ID)
+	return nil
+}
+
+func (GpaSummary) TableName() string { return "gpa_summaries" }