feat(docker-watcher): phase 11 - frontend embed & SSE

Embed SvelteKit static build in Go binary via go:embed. Event bus
for pub/sub with deploy log, instance status, and deploy status events.
SSE endpoints for real-time streaming. Frontend SSE client with
exponential backoff reconnection. Makefile for build pipeline.
Update Phase 12 auth plan with OAuth2/OIDC support.

internal/deployer/deployer.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/alexei/docker-watcher/internal/crypto"
 	"github.com/alexei/docker-watcher/internal/docker"
+	"github.com/alexei/docker-watcher/internal/events"
 	"github.com/alexei/docker-watcher/internal/health"
 	"github.com/alexei/docker-watcher/internal/notify"
 	"github.com/alexei/docker-watcher/internal/npm"
@@ -25,9 +26,15 @@ type Deployer struct {
 	store    *store.Store
 	health   *health.Checker
 	notifier *notify.Notifier
+	eventBus EventPublisher
 	encKey   [32]byte
 }
 
+// EventPublisher is the interface for publishing events to the event bus.
+type EventPublisher interface {
+	Publish(evt events.Event)
+}
+
 // New creates a new Deployer with all required dependencies.
 func New(
 	dockerClient *docker.Client,
@@ -35,6 +42,7 @@ func New(
 	st *store.Store,
 	checker *health.Checker,
 	notifier *notify.Notifier,
+	eventBus EventPublisher,
 	encKey [32]byte,
 ) *Deployer {
 	return &Deployer{
@@ -43,6 +51,7 @@ func New(
 		store:    st,
 		health:   checker,
 		notifier: notifier,
+		eventBus: eventBus,
 		encKey:   encKey,
 	}
 }
@@ -91,6 +100,7 @@ func (d *Deployer) TriggerDeploy(ctx context.Context, projectID, stageID, imageT
 
 	if deployErr != nil {
 		d.logDeploy(deploy.ID, fmt.Sprintf("Deploy failed: %v", deployErr), "error")
+		d.publishDeployStatus(deploy.ID, projectID, stageID, imageTag, "failed", deployErr.Error())
 		d.rollback(ctx, deploy.ID, containerID, npmProxyID, instanceID)
 
 		d.notifier.Send(settings.NotificationURL, notify.Event{
@@ -108,6 +118,7 @@ func (d *Deployer) TriggerDeploy(ctx context.Context, projectID, stageID, imageT
 	if err := d.store.UpdateDeployStatus(deploy.ID, "success", ""); err != nil {
 		log.Printf("deployer: update deploy status to success: %v", err)
 	}
+	d.publishDeployStatus(deploy.ID, projectID, stageID, imageTag, "success", "")
 
 	subdomain := d.buildSubdomain(project, stage, settings, imageTag)
 	fullURL := fmt.Sprintf("https://%s.%s", subdomain, settings.Domain)
@@ -144,6 +155,7 @@ func (d *Deployer) executeDeploy(
 	if err := d.store.UpdateDeployStatus(deployID, "pulling", ""); err != nil {
 		log.Printf("deployer: update deploy status: %v", err)
 	}
+	d.publishDeployStatus(deployID, project.ID, stage.ID, imageTag, "pulling", "")
 	d.logDeploy(deployID, fmt.Sprintf("Pulling image %s:%s", project.Image, imageTag), "info")
 
 	authConfig, err := d.buildRegistryAuth(project)
@@ -167,6 +179,7 @@ func (d *Deployer) executeDeploy(
 	if err := d.store.UpdateDeployStatus(deployID, "starting", ""); err != nil {
 		log.Printf("deployer: update deploy status: %v", err)
 	}
+	d.publishDeployStatus(deployID, project.ID, stage.ID, imageTag, "starting", "")
 
 	// Pre-generate instance ID so it can be set as a container label.
 	instanceID = uuid.New().String()
@@ -224,12 +237,14 @@ func (d *Deployer) executeDeploy(
 	if err := d.store.UpdateInstanceStatus(instanceID, "running"); err != nil {
 		log.Printf("deployer: update instance status to running: %v", err)
 	}
+	d.publishInstanceStatus(instanceID, project.ID, stage.ID, "running")
 	d.logDeploy(deployID, "Container started", "info")
 
 	// Step 4: Configure NPM proxy.
 	if err := d.store.UpdateDeployStatus(deployID, "configuring_proxy", ""); err != nil {
 		log.Printf("deployer: update deploy status: %v", err)
 	}
+	d.publishDeployStatus(deployID, project.ID, stage.ID, imageTag, "configuring_proxy", "")
 
 	npmProxyID, err = d.configureProxy(ctx, deployID, settings, containerName, project.Port, subdomain)
 	if err != nil {
@@ -248,6 +263,7 @@ func (d *Deployer) executeDeploy(
 		if err := d.store.UpdateDeployStatus(deployID, "health_checking", ""); err != nil {
 			log.Printf("deployer: update deploy status: %v", err)
 		}
+		d.publishDeployStatus(deployID, project.ID, stage.ID, imageTag, "health_checking", "")
 
 		healthURL := fmt.Sprintf("http://%s:%d%s", containerName, project.Port, project.Healthcheck)
 		d.logDeploy(deployID, fmt.Sprintf("Running health check: %s", healthURL), "info")
@@ -466,11 +482,54 @@ func (d *Deployer) parseEnvVars(envJSON string) []string {
 	return vars
 }
 
-// logDeploy appends a log entry for a deploy. Errors are logged to stderr but not propagated.
+// logDeploy appends a log entry for a deploy and publishes it on the event bus.
+// Errors are logged to stderr but not propagated.
 func (d *Deployer) logDeploy(deployID, message, level string) {
 	if err := d.store.AppendDeployLog(deployID, message, level); err != nil {
 		log.Printf("deployer: append deploy log: %v", err)
 	}
+	if d.eventBus != nil {
+		d.eventBus.Publish(events.Event{
+			Type: events.EventDeployLog,
+			Payload: events.DeployLogPayload{
+				DeployID: deployID,
+				Message:  message,
+				Level:    level,
+			},
+		})
+	}
+}
+
+// publishDeployStatus publishes a deploy status change event on the bus.
+func (d *Deployer) publishDeployStatus(deployID, projectID, stageID, imageTag, status, deployErr string) {
+	if d.eventBus != nil {
+		d.eventBus.Publish(events.Event{
+			Type: events.EventDeployStatus,
+			Payload: events.DeployStatusPayload{
+				DeployID:  deployID,
+				ProjectID: projectID,
+				StageID:   stageID,
+				ImageTag:  imageTag,
+				Status:    status,
+				Error:     deployErr,
+			},
+		})
+	}
+}
+
+// publishInstanceStatus publishes an instance status change event on the bus.
+func (d *Deployer) publishInstanceStatus(instanceID, projectID, stageID, status string) {
+	if d.eventBus != nil {
+		d.eventBus.Publish(events.Event{
+			Type: events.EventInstanceStatus,
+			Payload: events.InstanceStatusPayload{
+				InstanceID: instanceID,
+				ProjectID:  projectID,
+				StageID:    stageID,
+				Status:     status,
+			},
+		})
+	}
 }
 
 // truncateID safely truncates a Docker ID to 12 characters for display.