feat: make stdio server path configurable via MCP_SERVER_PATH env var

Add MCP_SERVER_PATH env var support for configuring the server binary path
in stdio mode. Update CLI help text to document new environment variables.

Co-authored-by: data-douser <70299490+data-douser@users.noreply.github.com>

Author: Copilot

client/src/lib/cli-parser.js

@@ -133,6 +133,12 @@ OPTIONS:
                        Example: --timeout 600
 
   --help               Display help information
+
+ENVIRONMENT VARIABLES:
+  MCP_MODE             MCP transport mode: stdio (default) or http
+  MCP_SERVER_PATH      Path to the MCP server JS entry point (stdio mode only)
+  MCP_SERVER_URL       MCP server URL (http mode only, default: http://localhost:3000/mcp)
+  ENABLE_MONITORING_TOOLS  Enable session_* monitoring tools (default: false)
 `;
 }
 

client/src/ql-mcp-client.js

@@ -123,13 +123,9 @@ class CodeQLMCPClient {
       });
 
       if (this.mcpMode === "stdio") {
-        const serverPath = path.join(
-          __dirname,
-          "..",
-          "server",
-          "dist",
-          "codeql-development-mcp-server.js"
-        );
+        const serverPath =
+          process.env.MCP_SERVER_PATH ||
+          path.join(__dirname, "..", "server", "dist", "codeql-development-mcp-server.js");
         this.transport = new StdioClientTransport({
           command: "node",
           args: [serverPath],