fix: fix flaky docker e2e tests and update python image

forge-go/e2e/distributed_client_test.go

@@ -180,6 +180,9 @@ agents:
 		statusKey := fmt.Sprintf("forge:agent:status:%s:%s", guildID, "echo-agent")
 		val, err := rdb.Get(context.Background(), statusKey).Result()
 		if err != nil {
+			if err == redis.Nil {
+				return fmt.Errorf("status key %q not written yet", statusKey)
+			}
 			return err
 		}
 		var status map[string]interface{}

forge-go/e2e/echo_test.go

@@ -166,6 +166,29 @@ func TestLevel1_EchoAgentIntegration(t *testing.T) {
 				}
 			}()
 
+			// For Docker, wait until the supervisor confirms the container is running before
+			// sending messages. This separates cold-start time from the message-exchange timeout.
+			if reqSup == "docker" {
+				statusKey := fmt.Sprintf("forge:agent:status:%s:%s", guildSpec.ID, agentSpec.ID)
+				require.NoError(t, waitFor(90*time.Second, 500*time.Millisecond, func() error {
+					val, err := rdb.Get(context.Background(), statusKey).Result()
+					if err == redis.Nil {
+						return fmt.Errorf("container not yet started")
+					}
+					if err != nil {
+						return err
+					}
+					var st map[string]interface{}
+					if err := json.Unmarshal([]byte(val), &st); err != nil {
+						return err
+					}
+					if state, _ := st["state"].(string); state != "running" {
+						return fmt.Errorf("container state: %q", state)
+					}
+					return nil
+				}), "Docker agent container did not reach running state")
+			}
+
 			// 6. Execute the core test assertions
 			// Send a payload to the topic the EchoAgent is configured to listen to.
 			testPayload := map[string]interface{}{
@@ -175,7 +198,7 @@ func TestLevel1_EchoAgentIntegration(t *testing.T) {
 			topicIn := fmt.Sprintf("%s:echo_topic", guildSpec.ID)
 			msg.TopicPublishedTo = topicIn
 
-			// Background routine to continually ping the agent until it finishes uvx boots and subscribes
+			// Background routine to continually ping the agent until it subscribes.
 			done := make(chan struct{})
 			go func() {
 				for {
@@ -188,8 +211,6 @@ func TestLevel1_EchoAgentIntegration(t *testing.T) {
 				}
 			}()
 
-			// Wait up to 30 seconds for the EchoAgent to receive, process, and publish a response
-			// Docker boots usually take ~3s the first time if cached, but we give 30s.
 			topicOut := fmt.Sprintf("%s:default_topic", guildSpec.ID)
 			respMsg, err := probeAgent.WaitForMessage(ctx, topicOut, 30*time.Second)
 			close(done)

forge-go/e2e/main_test.go

@@ -62,6 +62,11 @@ func TestMain(m *testing.M) {
 			fmt.Fprintf(os.Stderr, "failed to build e2e forge binary: %v\n%s\n", buildErr, string(buildOut))
 			os.Exit(1)
 		}
+
+		// Pre-pull the default Docker agent image so individual tests don't time out on a cold pull.
+		if out, err := exec.Command("docker", "pull", "ghcr.io/astral-sh/uv:python3.13-bookworm-slim").CombinedOutput(); err != nil {
+			fmt.Fprintf(os.Stderr, "docker pre-pull (non-fatal): %v\n%s\n", err, out)
+		}
 	}
 	code := m.Run()
 	if e2eBaseDir != "" {

forge-go/supervisor/docker.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"os"
 	"os/user"
 	"path/filepath"
 	"strings"
@@ -209,7 +210,7 @@ func (d *DockerSupervisor) Launch(ctx context.Context, guildID string, agentSpec
 
 	imageRef := entry.Image
 	if imageRef == "" {
-		imageRef = "ghcr.io/astral-sh/uv:python3.12-bookworm-slim"
+		imageRef = "ghcr.io/astral-sh/uv:python3.13-bookworm-slim"
 	}
 
 	if err := d.ensureImage(ctx, imageRef); err != nil {
@@ -218,13 +219,14 @@ func (d *DockerSupervisor) Launch(ctx context.Context, guildID string, agentSpec
 
 	env = append(env, "UV_PROJECT_ENVIRONMENT=/tmp/.venv")
 
-	var cleanEnv []string
+	// Extract UV_CACHE_DIR so we can bind-mount it into the container for caching.
+	var uvCacheDir string
 	for _, e := range env {
-		if !strings.HasPrefix(e, "UV_CACHE_DIR=") {
-			cleanEnv = append(cleanEnv, e)
+		if val, ok := strings.CutPrefix(e, "UV_CACHE_DIR="); ok {
+			uvCacheDir = val
+			break
 		}
 	}
-	env = cleanEnv
 
 	var cmd []string
 	if entry.Runtime == registry.RuntimeDocker {
@@ -266,6 +268,13 @@ func (d *DockerSupervisor) Launch(ctx context.Context, guildID string, agentSpec
 
 	containerCfg, hostCfg := BuildContainerConfig(agentSpec, entry, guildID, imageRef, cmd, env)
 
+	// Mount the UV cache directory so repeated runs reuse cached packages.
+	if uvCacheDir != "" {
+		if err := os.MkdirAll(uvCacheDir, 0o755); err == nil {
+			hostCfg.Binds = append(hostCfg.Binds, fmt.Sprintf("%s:%s:rw,z", uvCacheDir, uvCacheDir))
+		}
+	}
+
 	// Adjust container config for bridge connectivity.
 	if bridge != nil {
 		if bridge.Mode() == BridgeTransportIPC {
@@ -413,7 +422,7 @@ func (d *DockerSupervisor) relaunchContainer(ctx context.Context, guildID string
 
 	imageRef := entry.Image
 	if imageRef == "" {
-		imageRef = "ghcr.io/astral-sh/uv:python3.12-bookworm-slim"
+		imageRef = "ghcr.io/astral-sh/uv:python3.13-bookworm-slim"
 	}
 
 	var cmd []string

forge-go/supervisor/docker_test.go

@@ -27,11 +27,11 @@ func TestBuildContainerConfig_Airgapped(t *testing.T) {
 	cmd := []string{"python", "main.py"}
 	env := []string{"FOO=BAR"}
 
-	cCfg, hCfg := BuildContainerConfig(agentSpec, entry, "test-guild", "ghcr.io/astral-sh/uv:python3.12-bookworm-slim", cmd, env)
+	cCfg, hCfg := BuildContainerConfig(agentSpec, entry, "test-guild", "ghcr.io/astral-sh/uv:python3.13-bookworm-slim", cmd, env)
 
 	// Image
-	if cCfg.Image != "ghcr.io/astral-sh/uv:python3.12-bookworm-slim" {
-		t.Errorf("expected image ghcr.io/astral-sh/uv:python3.12-bookworm-slim, got %s", cCfg.Image)
+	if cCfg.Image != "ghcr.io/astral-sh/uv:python3.13-bookworm-slim" {
+		t.Errorf("expected image ghcr.io/astral-sh/uv:python3.13-bookworm-slim, got %s", cCfg.Image)
 	}
 
 	// Command