feat: add read_file tool

mcp/server.ts

@@ -35,6 +35,7 @@ import {
   GetReviewCommentsTool,
   ListPullRequestReviewsTool,
 } from "./reviewComments.ts";
+import { ReadFileTool } from "./readFile.ts";
 import { SelectModeTool } from "./selectMode.ts";
 import { addTools } from "./shared.ts";
 import { KillBackgroundTool, ShellTool } from "./shell.ts";
@@ -118,6 +119,7 @@ function buildCommonTools(ctx: ToolContext, outputSchema?: JsonSchema): Tool<any
     GitTool(ctx),
     GitFetchTool(ctx),
     UploadFileTool(ctx),
+    ReadFileTool(ctx),
   ];
 
   const isStandalone = ctx.payload.event.trigger === "unknown";