refactor: shorten model and table prefixes

backend/internal/models/project.go

@@ -2,7 +2,7 @@ package models
 
 import "time"
 
-type SenlinAgentProject struct {
+type SaProject struct {
 	ID            uint   `gorm:"primaryKey"`
 	Identity      string `gorm:"type:char(36);uniqueIndex"`
 	OwnerID       uint   `gorm:"index;not null"`
@@ -16,6 +16,6 @@ type SenlinAgentProject struct {
 	UpdatedAt     time.Time
 }
 
-func (SenlinAgentProject) TableName() string {
-	return "senlin_agent_projects"
+func (SaProject) TableName() string {
+	return "sa_projects"
 }