Feat v0.9.3 team user roles (#77)

Co-authored-by: Jeffrey Smith <jasafpro@gmail.com>
Co-committed-by: Jeffrey Smith <jasafpro@gmail.com>

server/models/models.go

@@ -80,6 +80,16 @@ type TeamMember struct {
 	Username    string `json:"username,omitempty"`
 }
 
+// TeamUserRole is a many-to-many join: one user can hold multiple roles in a team.
+type TeamUserRole struct {
+	ID         string `json:"id" db:"id"`
+	TeamID     string `json:"team_id" db:"team_id"`
+	UserID     string `json:"user_id" db:"user_id"`
+	Role       string `json:"role" db:"role"`
+	AssignedBy string `json:"assigned_by,omitempty" db:"assigned_by"`
+	AssignedAt string `json:"assigned_at" db:"assigned_at"`
+}
+
 // PLATFORM POLICIES
 
 var PolicyDefaults = map[string]string{