feat: Misskey channel adapter, agent reliability hardening & stream error resilience (#359)

internal/email/adapters/generic/adapter.go

@@ -135,7 +135,7 @@ func (a *Adapter) StartReceiving(ctx context.Context, config map[string]any, han
 
 	providerID, _ := config["_provider_id"].(string)
 
-	rctx, cancel := context.WithCancel(ctx)
+	rctx, cancel := context.WithCancel(ctx) //nolint:gosec // G118: cancel is stored in conn.cancel and called by Stop()
 	conn := &imapConn{
 		logger:       a.logger,
 		host:         host,

internal/email/adapters/gmail/adapter.go

@@ -146,7 +146,7 @@ func (a *Adapter) Send(ctx context.Context, config map[string]any, msg email.Out
 
 func (a *Adapter) StartReceiving(ctx context.Context, config map[string]any, handler email.InboundHandler) (email.Stopper, error) {
 	providerID, _ := config["_provider_id"].(string)
-	rctx, cancel := context.WithCancel(ctx)
+	rctx, cancel := context.WithCancel(ctx) //nolint:gosec // G118: cancel is stored in conn.cancel and called by Stop()
 	conn := &gmailImapConn{
 		adapter:    a,
 		config:     config,

internal/email/adapters/mailgun/adapter.go

@@ -122,7 +122,7 @@ func (a *Adapter) StartReceiving(ctx context.Context, config map[string]any, han
 	providerID, _ := config["_provider_id"].(string)
 	domain, _ := config["domain"].(string)
 
-	rctx, cancel := context.WithCancel(ctx)
+	rctx, cancel := context.WithCancel(ctx) //nolint:gosec // G118: cancel is stored in conn.cancel and called by Stop()
 	conn := &pollConn{
 		logger:       a.logger,
 		client:       newClient(config),