feat: standardize file headers and convert Node test files to templates

- Add {{>api_info}} partial to all source templates in Python, PHP,
  Elixir, and Ruby for consistent file headers across all 12 languages
- Replace {{>partial_header}} with {{>api_info}} in PHP and Python,
  delete redundant partial_header.mustache files
- Convert 10 static Node .ts test files to .mustache templates with
  {{importFileExtension}} support
- Fix renderOptionsTemplate to support Mustache partials via template
  loader and inject additionalProperties into options context
- Rename Go Makefile fmt target to format for consistency
- Add lint and analyze targets to C# Makefile

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mridang

src/main/java/io/github/mridang/codegen/generators/AbstractBetterCodegen.java

@@ -12,6 +12,7 @@
 import io.swagger.v3.oas.models.tags.Tag;
 import java.io.BufferedReader;
 import java.io.File;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -1472,6 +1473,9 @@ protected void writeFile(String filePath, String content) {
      * apiTemplateFiles mechanism cannot produce per-operation files.
      */
     protected String renderOptionsTemplate(String templateName, Map<String, Object> context) {
+        for (Map.Entry<String, Object> entry : additionalProperties.entrySet()) {
+            context.putIfAbsent(entry.getKey(), entry.getValue());
+        }
         final String templatePath = embeddedTemplateDir + "/" + templateName;
         try (InputStream is =
                         getClass().getClassLoader().getResourceAsStream(templatePath);
@@ -1480,7 +1484,25 @@ protected String renderOptionsTemplate(String templateName, Map<String, Object>
                                 Objects.requireNonNull(
                                         is, "Template not found: " + templatePath),
                                 StandardCharsets.UTF_8)) {
-            return Mustache.compiler().escapeHTML(false).compile(reader).execute(context);
+            return Mustache.compiler()
+                    .escapeHTML(false)
+                    .withLoader(
+                            name -> {
+                                String partialPath =
+                                        embeddedTemplateDir + "/" + name + ".mustache";
+                                InputStream partialIs =
+                                        getClass()
+                                                .getClassLoader()
+                                                .getResourceAsStream(partialPath);
+                                if (partialIs == null) {
+                                    throw new FileNotFoundException(
+                                            "Partial not found: " + partialPath);
+                                }
+                                return new InputStreamReader(
+                                        partialIs, StandardCharsets.UTF_8);
+                            })
+                    .compile(reader)
+                    .execute(context);
         } catch (IOException e) {
             throw new UncheckedIOException("Failed to render template: " + templatePath, e);
         }

src/main/java/io/github/mridang/codegen/generators/node/BetterNodeCodegen.java

@@ -313,22 +313,22 @@ public void processOpts() {
             supportingFiles.add(new SupportingFile("test/setup.ts", "test", "setup.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/Api/pet-api.test.ts",
+                            "test/Api/pet-api.test.mustache",
                             Path.of("test", "Api").toString(),
                             "pet-api.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/Api/store-api.test.ts",
+                            "test/Api/store-api.test.mustache",
                             Path.of("test", "Api").toString(),
                             "store-api.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/default-api-client.test.ts",
+                            "test/default-api-client.test.mustache",
                             "test",
                             "default-api-client.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/default-api-client-unit.test.ts",
+                            "test/default-api-client-unit.test.mustache",
                             "test",
                             "default-api-client-unit.test.ts"));
             supportingFiles.add(
@@ -338,17 +338,17 @@ public void processOpts() {
                             "transport-options.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/object-serializer.test.ts",
+                            "test/object-serializer.test.mustache",
                             "test",
                             "object-serializer.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/value-serializer.test.ts",
+                            "test/value-serializer.test.mustache",
                             "test",
                             "value-serializer.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/trace-context-util.test.ts",
+                            "test/trace-context-util.test.mustache",
                             "test",
                             "trace-context-util.test.ts"));
             supportingFiles.add(
@@ -358,17 +358,17 @@ public void processOpts() {
                             "base-api.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/metadata.test.ts",
+                            "test/metadata.test.mustache",
                             "test",
                             "metadata.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/composed-schema.test.ts",
+                            "test/composed-schema.test.mustache",
                             "test",
                             "composed-schema.test.ts"));
             supportingFiles.add(
                     new SupportingFile(
-                            "test/header-selector.test.ts",
+                            "test/header-selector.test.mustache",
                             "test",
                             "header-selector.test.ts"));
             supportingFiles.add(

src/main/resources/templates/csharp/makefile.mustache

@@ -1,14 +1,20 @@
-.PHONY: build test format docs clean
+.PHONY: build test lint format analyze docs clean
 
 build:
 	dotnet build
 
 test:
 	dotnet test --verbosity normal
 
+lint:
+	dotnet csharpier --check .
+
 format:
 	dotnet csharpier .
 
+analyze:
+	dotnet build --no-restore /warnaserror
+
 docs:
 	dotnet build /p:DocumentationFile=docs/api.xml
 

src/main/resources/templates/elixir/api/api.mustache

@@ -1,13 +1,4 @@
-{{#appName}}
-# {{{.}}}
-{{/appName}}
-{{#appDescription}}
-# {{{.}}}
-{{/appDescription}}
-#
-# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
-#
-# Generated by: https://openapi-generator.tech
+{{>api_info}}
 
 defmodule {{moduleName}}.Api do
   @moduledoc """

src/main/resources/templates/elixir/api/options.mustache

@@ -1,3 +1,5 @@
+{{>api_info}}
+
 defmodule {{moduleName}}.Api.Options.{{className}} do
   @moduledoc """
   Options for the `{{operationId}}` operation.

src/main/resources/templates/elixir/api_client.mustache

@@ -1,13 +1,4 @@
-{{#appName}}
-# {{{.}}}
-{{/appName}}
-{{#appDescription}}
-# {{{.}}}
-{{/appDescription}}
-#
-# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
-#
-# Generated by: https://openapi-generator.tech
+{{>api_info}}
 
 defmodule {{moduleName}}.ApiClient do
   @moduledoc """

src/main/resources/templates/elixir/api_error.mustache

@@ -1,13 +1,4 @@
-{{#appName}}
-# {{{.}}}
-{{/appName}}
-{{#appDescription}}
-# {{{.}}}
-{{/appDescription}}
-#
-# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
-#
-# Generated by: https://openapi-generator.tech
+{{>api_info}}
 
 defmodule {{moduleName}}.ApiError do
   @moduledoc """

src/main/resources/templates/elixir/api_info.mustache

@@ -0,0 +1,10 @@
+{{#appName}}
+# {{{.}}}
+{{/appName}}
+{{#appDescription}}
+# {{{.}}}
+{{/appDescription}}
+#
+# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
+#
+# Generated by: https://openapi-generator.tech

src/main/resources/templates/elixir/api_response.mustache

@@ -1,13 +1,4 @@
-{{#appName}}
-# {{{.}}}
-{{/appName}}
-{{#appDescription}}
-# {{{.}}}
-{{/appDescription}}
-#
-# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
-#
-# Generated by: https://openapi-generator.tech
+{{>api_info}}
 
 defmodule {{moduleName}}.ApiResponse do
   @moduledoc """

src/main/resources/templates/elixir/api_result.mustache

@@ -1,13 +1,4 @@
-{{#appName}}
-# {{{.}}}
-{{/appName}}
-{{#appDescription}}
-# {{{.}}}
-{{/appDescription}}
-#
-# The version of the OpenAPI document: {{#version}}{{{.}}}{{/version}}
-#
-# Generated by: https://openapi-generator.tech
+{{>api_info}}
 
 defmodule {{moduleName}}.ApiResult do
   @moduledoc """