feat(desktop): push publish tasks via AMQP topic dispatch WebSocket

Introduce a desktop.task.dispatch topic exchange with per-client routing
keys. Tenant-api publishes a task_available frame keyed by target client
ID when a publish job is created; every instance binds its own transient
queue and forwards to the matching WebSocket (/api/desktop/dispatch) it
owns. Desktop-client now prefers this push channel and only falls back
to HTTP /lease polling when the socket is down. Also drop admin-web
monitoring-plugin remnants and scope the publish modal account list to
publish platforms.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/shared/messaging/rabbitmq/client.go

@@ -46,6 +46,16 @@ func New(_ context.Context, cfg config.RabbitMQConfig) (*Client, error) {
 	return client, nil
 }
 
+// Config returns a copy of the effective rabbitmq configuration. Services that
+// need to derive routing keys (e.g. desktop dispatch) consult this instead of
+// hard-coding string constants.
+func (c *Client) Config() config.RabbitMQConfig {
+	if c == nil {
+		return config.RabbitMQConfig{}
+	}
+	return c.cfg
+}
+
 func (c *Client) Close() error {
 	if c == nil {
 		return nil
@@ -102,6 +112,91 @@ func (c *Client) PublishDesktopTaskEvent(ctx context.Context, body []byte) error
 	return c.publishFanout(ctx, c.cfg.DesktopTaskEventExchange, body)
 }
 
+func (c *Client) PublishDesktopDispatch(ctx context.Context, routingKey string, body []byte) error {
+	return c.publish(ctx, c.cfg.DesktopDispatchExchange, routingKey, body)
+}
+
+// ConsumeDesktopDispatch declares a transient per-process queue bound to the
+// desktop dispatch topic exchange using bindingKeys, and begins consuming from
+// it. Every tenant-api instance gets its own queue so every instance sees every
+// dispatch message; the hub inside the instance then filters by target client
+// presence. Messages are auto-ack (transient delivery is OK: if the instance
+// dies, the client reconnects and the server re-drives the task via the
+// existing lease/recovery path).
+func (c *Client) ConsumeDesktopDispatch(consumerName string, bindingKeys []string) (<-chan amqp.Delivery, *amqp.Channel, error) {
+	if len(bindingKeys) == 0 {
+		return nil, nil, fmt.Errorf("consume rabbitmq desktop dispatch: bindingKeys is required")
+	}
+
+	for attempt := 0; attempt < 2; attempt++ {
+		conn, ch, err := c.openChannel()
+		if err != nil {
+			return nil, nil, err
+		}
+
+		queue, err := ch.QueueDeclare(
+			"",
+			false,
+			true,
+			true,
+			false,
+			nil,
+		)
+		if err != nil {
+			_ = ch.Close()
+			c.invalidateConnection(conn)
+			if attempt == 1 {
+				return nil, nil, fmt.Errorf("declare rabbitmq desktop dispatch queue: %w", err)
+			}
+			continue
+		}
+
+		bindFailed := false
+		for _, key := range bindingKeys {
+			if err := ch.QueueBind(
+				queue.Name,
+				key,
+				c.cfg.DesktopDispatchExchange,
+				false,
+				nil,
+			); err != nil {
+				_ = ch.Close()
+				c.invalidateConnection(conn)
+				if attempt == 1 {
+					return nil, nil, fmt.Errorf("bind rabbitmq desktop dispatch queue: %w", err)
+				}
+				bindFailed = true
+				break
+			}
+		}
+		if bindFailed {
+			continue
+		}
+
+		deliveries, err := ch.Consume(
+			queue.Name,
+			consumerName,
+			true,
+			true,
+			false,
+			false,
+			nil,
+		)
+		if err != nil {
+			_ = ch.Close()
+			c.invalidateConnection(conn)
+			if attempt == 1 {
+				return nil, nil, fmt.Errorf("consume rabbitmq desktop dispatch queue: %w", err)
+			}
+			continue
+		}
+
+		return deliveries, ch, nil
+	}
+
+	return nil, nil, fmt.Errorf("consume rabbitmq desktop dispatch queue: retry exhausted")
+}
+
 func (c *Client) PublishTemplateAssistTask(ctx context.Context, body []byte) error {
 	return c.publish(ctx, c.cfg.TemplateAssistExchange, c.cfg.TemplateAssistRoutingKey, body)
 }
@@ -578,6 +673,18 @@ func (c *Client) ensureTopology(conn *amqp.Connection) error {
 		return fmt.Errorf("declare rabbitmq exchange %s: %w", c.cfg.DesktopTaskEventExchange, err)
 	}
 
+	if err := ch.ExchangeDeclare(
+		c.cfg.DesktopDispatchExchange,
+		"topic",
+		true,
+		false,
+		false,
+		false,
+		nil,
+	); err != nil {
+		return fmt.Errorf("declare rabbitmq exchange %s: %w", c.cfg.DesktopDispatchExchange, err)
+	}
+
 	if err := c.ensureWorkQueue(
 		ch,
 		c.cfg.TemplateAssistExchange,