feat: password reset

internal/model/user.go

@@ -1,6 +1,9 @@
 package model
 
-import "time"
+import (
+	"encoding/json"
+	"time"
+)
 
 // User represents a row in the `users` table.
 //
@@ -14,7 +17,10 @@ import "time"
 // frontend uses this to decide whether to show the "verify your email" ribbon.
 type User struct {
 	ID              string     `json:"id"`
-	Email           string     `json:"email"`
+	// Email is nullable: OAuth users (typically Facebook accounts with no
+	// verified email on file) sign up without one and can fill it in later
+	// from their profile.
+	Email           *string    `json:"email"`
 	Handle          string     `json:"handle"`
 	Name            string     `json:"name"`
 	AvatarURL       *string    `json:"avatar_url"`
@@ -27,6 +33,20 @@ type User struct {
 	UpdatedAt       time.Time  `json:"updated_at"`
 }
 
+// MarshalJSON adds a derived `has_password` flag so the frontend can pick
+// "Change password" vs "Set a password" for OAuth-only accounts, without
+// the password hash itself ever leaving the server.
+func (u User) MarshalJSON() ([]byte, error) {
+	type alias User
+	return json.Marshal(&struct {
+		alias
+		HasPassword bool `json:"has_password"`
+	}{
+		alias:       alias(u),
+		HasPassword: u.PasswordHash != nil,
+	})
+}
+
 // AuthToken represents a row in the `auth_tokens` table.
 // Used for both password reset and email verification flows.
 type AuthToken struct {