Fix MCP config not being passed to Claude CLI

The MCP servers (including github_comment server) were configured but not passed to Claude. This caused the "update_claude_comment" tool to be unavailable.

Changes:
- Write MCP config to a file at $RUNNER_TEMP/claude-mcp-config.json
- Add mcp_config_file output from prepare.ts
- Pass MCP config file via --mcp-config flag in claude_args
- Use fs/promises writeFile to match codebase conventions

action.yml

@@ -160,7 +160,7 @@ runs:
         INPUT_PROMPT_FILE: ${{ runner.temp }}/claude-prompts/claude-prompt.txt
         INPUT_SETTINGS: ${{ inputs.settings }}
         INPUT_TIMEOUT_MINUTES: ${{ inputs.timeout_minutes }}
-        INPUT_CLAUDE_ARGS: ${{ inputs.claude_args }}
+        INPUT_CLAUDE_ARGS: ${{ steps.prepare.outputs.mcp_config_file && format('--mcp-config {0} {1}', steps.prepare.outputs.mcp_config_file, inputs.claude_args) || inputs.claude_args }}
         INPUT_EXPERIMENTAL_SLASH_COMMANDS_DIR: ${{ github.action_path }}/slash-commands
 
         # Model configuration

src/entrypoints/prepare.ts

@@ -6,6 +6,7 @@
  */
 
 import * as core from "@actions/core";
+import { writeFile } from "fs/promises";
 import { setupGitHubToken } from "../github/token";
 import { checkWritePermissions } from "../github/validation/permissions";
 import { createOctokit } from "../github/api/client";
@@ -57,8 +58,11 @@ async function run() {
       githubToken,
     });
 
-    // Set the MCP config output
+    // Write MCP config to a file and set the file path as output
+    const mcpConfigPath = `${process.env.RUNNER_TEMP}/claude-mcp-config.json`;
+    await writeFile(mcpConfigPath, result.mcpConfig);
     core.setOutput("mcp_config", result.mcpConfig);
+    core.setOutput("mcp_config_file", mcpConfigPath);
 
     // Step 6: Get system prompt from mode if available
     if (mode.getSystemPrompt) {

test/mockContext.ts

@@ -27,8 +27,8 @@ const defaultRepository = {
   full_name: "test-owner/test-repo",
 };
 
-type MockContextOverrides = Omit<Partial<ParsedGitHubContext>, 'inputs'> & {
-  inputs?: Partial<ParsedGitHubContext['inputs']>;
+type MockContextOverrides = Omit<Partial<ParsedGitHubContext>, "inputs"> & {
+  inputs?: Partial<ParsedGitHubContext["inputs"]>;
 };
 
 export const createMockContext = (
@@ -53,8 +53,8 @@ export const createMockContext = (
   return { ...baseContext, ...overrides, inputs: mergedInputs };
 };
 
-type MockAutomationOverrides = Omit<Partial<AutomationContext>, 'inputs'> & {
-  inputs?: Partial<AutomationContext['inputs']>;
+type MockAutomationOverrides = Omit<Partial<AutomationContext>, "inputs"> & {
+  inputs?: Partial<AutomationContext["inputs"]>;
 };
 
 export const createMockAutomationContext = (