fix(cmd): unwrap build errors, remove premature startup message (#180)

Author: speedo17

internal/cmd/root.go

@@ -123,10 +123,9 @@ var rootCmd = &cobra.Command{
 		}
 
 		if !running {
-			_, _ = color.New(color.FgCyan).Printf("Starting workspace %s...\n", ws.Name)
 			workspaceExplicit = true
 			if err := runUp(ctx, nil); err != nil {
-				return fmt.Errorf("start workspace %q: %w", ws.Name, err)
+				return err
 			}
 			_, _ = color.New(color.FgCyan).Printf("Waiting for OpenCode to be ready...\n")
 			if err := waitForReadiness(ctx, ws.Port, ws.ExposePort, client); err != nil {

internal/docker/docker.go

@@ -628,6 +628,12 @@ func BuildOverlayImage(ctx context.Context, base string, ws workspace.Resolved)
 		return "", fmt.Errorf("close temporary workspace Dockerfile %q: %w", tmpDockerfilePath, err)
 	}
 
+	// Workspace overlays are rebuilt unconditionally on every workspace startup.
+	// We do NOT check whether overlayTag already exists locally and skip the build —
+	// that would silently run a stale image when the user edits their Dockerfile
+	// but the edit produces a build error. Build failure must abort startup.
+	// Daemon-side layer cache already provides the fast path for unchanged Dockerfiles;
+	// adding a second cache layer here would only mask user errors.
 	hash := sha256.Sum256(dockerfileContent)
 	hashHex := fmt.Sprintf("%x", hash)
 	overlayTag := fmt.Sprintf("jailoc-%s:%s", ws.Name, hashHex[:8])