Add BuildArgs support to TemplateData and all templates

- Add BuildArgs field to TemplateData struct for baking required CLI
  arguments into container ENTRYPOINT at build time
- Update npx.tmpl to insert BuildArgs before "$@"
- Update uvx.tmpl to insert BuildArgs before "$@"
- Update go.tmpl to insert BuildArgs in JSON array format

BuildArgs are for required subcommands (e.g., 'start') while runtime
args passed via '-- <args>' append after. This prevents duplication
issues that led to MCPArgs removal in PR #2630.

Related to: stacklok/dockyard#189

Author: danbarr

pkg/container/templates/go.tmpl

@@ -99,4 +99,4 @@ COPY --from=builder --chown=appuser:appgroup /build/ /app/
 USER appuser
 
 # Run the pre-built MCP server binary
-ENTRYPOINT ["/app/mcp-server"]
+ENTRYPOINT ["/app/mcp-server"{{range .BuildArgs}}, "{{.}}{{end}}"]

pkg/container/templates/npx.tmpl

@@ -98,7 +98,7 @@ USER appuser
 # `MCPPackage` may include a version suffix (e.g., `[email protected]`), which we cannot use here.
 # Create a small wrapper script to handle this.
 RUN echo "#!/bin/sh" >> entrypoint.sh && \
-    echo "exec npx {{.MCPPackage}} \"\$@\"" >> entrypoint.sh && \
+    echo "exec npx {{.MCPPackage}}{{range .BuildArgs}} {{.}}{{end}} \"\$@\"" >> entrypoint.sh && \
     chmod +x entrypoint.sh
 
 # Run the preinstalled MCP package directly using npx.

pkg/container/templates/templates.go

@@ -20,6 +20,10 @@ type TemplateData struct {
 	CACertContent string
 	// IsLocalPath indicates if the MCPPackage is a local path that should be copied into the container.
 	IsLocalPath bool
+	// BuildArgs are the arguments to bake into the container's ENTRYPOINT at build time.
+	// These are typically required subcommands (e.g., "start") that must always be present.
+	// Runtime arguments passed via "-- <args>" will be appended after these build args.
+	BuildArgs []string
 }
 
 // TransportType represents the type of transport to use.

pkg/container/templates/uvx.tmpl

@@ -118,4 +118,4 @@ USER appuser
 # We use sh -c to allow the package name to be resolved from PATH
 # Strip version specifier (if present) from package name for execution
 # Handles format like package@version
-ENTRYPOINT ["sh", "-c", "package='{{.MCPPackage}}'; exec \"${package%%@*}\"", "--"]
+ENTRYPOINT ["sh", "-c", "package='{{.MCPPackage}}'; exec \"${package%%@*}\"{{range .BuildArgs}} \"{{.}}\"{{end}}", "--"]