fix: only load GitHub MCP server when its tools are allowed (#124)

* fix: only load GitHub MCP server when its tools are allowed

- Add allowedTools parameter to prepareMcpConfig
- Check for mcp__github__ and mcp__github_file_ops__ tool prefixes
- Only include MCP servers when their tools are in allowed_tools
- Maintain backward compatibility when allowed_tools is not specified
- Update tests to reflect the new conditional loading behavior

This optimizes resource usage by not loading unnecessary MCP servers
when their tools are not allowed in the configuration.

Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

* fix: always load github_file_ops server regardless of allowed_tools

- Only apply conditional loading to the github MCP server
- Always load github_file_ops server as it contains essential tools
- Update tests to reflect this behavior

Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

* refactor: move allowedTools/disallowedTools parsing to parseGitHubContext

- Change allowedTools and disallowedTools from string to string[] in ParsedGitHubContext type
- Parse comma-separated environment variables into arrays in parseGitHubContext function
- Update create-prompt and install-mcp-server to use pre-parsed arrays
- Update all affected test files to use array syntax
- Eliminate duplicate parsing logic across the codebase

* style: apply prettier formatting

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

src/mcp/install-mcp-server.ts

@@ -7,6 +7,7 @@ type PrepareConfigParams = {
   branch: string;
   additionalMcpConfig?: string;
   claudeCommentId?: string;
+  allowedTools: string[];
 };
 
 export async function prepareMcpConfig(
@@ -19,24 +20,17 @@ export async function prepareMcpConfig(
     branch,
     additionalMcpConfig,
     claudeCommentId,
+    allowedTools,
   } = params;
   try {
-    const baseMcpConfig = {
+    const allowedToolsList = allowedTools || [];
+
+    const hasGitHubMcpTools = allowedToolsList.some((tool) =>
+      tool.startsWith("mcp__github__"),
+    );
+
+    const baseMcpConfig: { mcpServers: Record<string, unknown> } = {
       mcpServers: {
-        github: {
-          command: "docker",
-          args: [
-            "run",
-            "-i",
-            "--rm",
-            "-e",
-            "GITHUB_PERSONAL_ACCESS_TOKEN",
-            "ghcr.io/github/github-mcp-server:sha-e9f748f", // https://github.com/github/github-mcp-server/releases/tag/v0.4.0
-          ],
-          env: {
-            GITHUB_PERSONAL_ACCESS_TOKEN: githubToken,
-          },
-        },
         github_file_ops: {
           command: "bun",
           args: [
@@ -57,6 +51,23 @@ export async function prepareMcpConfig(
       },
     };
 
+    if (hasGitHubMcpTools) {
+      baseMcpConfig.mcpServers.github = {
+        command: "docker",
+        args: [
+          "run",
+          "-i",
+          "--rm",
+          "-e",
+          "GITHUB_PERSONAL_ACCESS_TOKEN",
+          "ghcr.io/github/github-mcp-server:sha-e9f748f", // https://github.com/github/github-mcp-server/releases/tag/v0.4.0
+        ],
+        env: {
+          GITHUB_PERSONAL_ACCESS_TOKEN: githubToken,
+        },
+      };
+    }
+
     // Merge with additional MCP config if provided
     if (additionalMcpConfig && additionalMcpConfig.trim()) {
       try {