[bugfix] serialize instance terms via API (#2293)

internal/api/model/instancev1.go

@@ -90,6 +90,8 @@ type InstanceV1 struct {
 	MaxTootChars uint `json:"max_toot_chars"`
 	// An itemized list of rules for this instance.
 	Rules []InstanceRule `json:"rules"`
+	// Terms and conditions for accounts on this instance.
+	Terms string `json:"terms,omitempty"`
 }
 
 // InstanceV1URLs models instance-relevant URLs for client application consumption.

internal/api/model/instancev2.go

@@ -64,6 +64,8 @@ type InstanceV2 struct {
 	Contact InstanceV2Contact `json:"contact"`
 	// An itemized list of rules for this instance.
 	Rules []InstanceRule `json:"rules"`
+	// Terms and conditions for accounts on this instance.
+	Terms string `json:"terms,omitempty"`
 }
 
 // Usage data for this instance.

internal/typeutils/internaltofrontend.go

@@ -805,6 +805,7 @@ func (c *Converter) InstanceToAPIV1Instance(ctx context.Context, i *gtsmodel.Ins
 		InvitesEnabled:   false, // todo: not supported yet
 		MaxTootChars:     uint(config.GetStatusesMaxChars()),
 		Rules:            c.InstanceRulesToAPIRules(i.Rules),
+		Terms:            i.Terms,
 	}
 
 	if config.GetInstanceInjectMastodonVersion() {
@@ -909,6 +910,7 @@ func (c *Converter) InstanceToAPIV2Instance(ctx context.Context, i *gtsmodel.Ins
 		Usage:         apimodel.InstanceV2Usage{}, // todo: not implemented
 		Languages:     []string{},                 // todo: not implemented
 		Rules:         c.InstanceRulesToAPIRules(i.Rules),
+		Terms:         i.Terms,
 	}
 
 	if config.GetInstanceInjectMastodonVersion() {