feat(code): add .worktreeinclude support (#1344)

## Problem

tragically, i think we really should make worktrees work well

<!-- Who is this for and what problem does it solve? -->

<!-- Closes #ISSUE_ID -->

## Changes

less tragically, i think this small change makes it all better :)

- added support for `.worktreeinclude` and `.worktreelink` files
- they do what they sound like; `include` copies files and `link` symlinks files
- both are filtered to only include files that are gitignored, which [matches cc's implementation](https://code.claude.com/docs/en/common-workflows#copy-gitignored-files-to-worktrees) 


<!-- What did you change and why? -->
<!-- If there are frontend changes, include screenshots. -->

## How did you test this?

added these tiny pieces to the main repo, and it all works pretty smoothly: https://app.graphite.com/github/pr/PostHog/posthog/52566

<!-- Describe what you tested -- manual steps, automated tests, or both. -->
<!-- If you're an agent, only list tests you actually ran. -->

Author: adboio

apps/code/src/renderer/features/environments/components/EnvironmentSelector.tsx

@@ -4,7 +4,7 @@ import { HardDrives, Plus } from "@phosphor-icons/react";
 import { Flex, Tooltip } from "@radix-ui/themes";
 import { useTRPC } from "@renderer/trpc/client";
 import { useQuery } from "@tanstack/react-query";
-import { useState } from "react";
+import { useEffect, useState } from "react";
 
 interface EnvironmentSelectorProps {
   repoPath: string | null;
@@ -29,6 +29,12 @@ export function EnvironmentSelector({
     enabled: !!repoPath,
   });
 
+  useEffect(() => {
+    if (value === null && environments.length > 0) {
+      onChange(environments[0].id);
+    }
+  }, [value, environments, onChange]);
+
   const selectedEnvironment = environments.find((env) => env.id === value);
   const displayText = selectedEnvironment?.name ?? "No environment";
 

packages/agent/src/adapters/claude/claude-agent.ts

@@ -88,7 +88,7 @@ import type {
   ToolUseCache,
 } from "./types";
 
-const SESSION_VALIDATION_TIMEOUT_MS = 10_000;
+const SESSION_VALIDATION_TIMEOUT_MS = 30_000;
 const MAX_TITLE_LENGTH = 256;
 const LOCAL_ONLY_COMMANDS = new Set(["/context", "/heapdump", "/extra-usage"]);
 

packages/git/src/queries.ts

@@ -971,8 +971,17 @@ export async function addToLocalExclude(
   pattern: string,
   options?: CreateGitClientOptions,
 ): Promise<void> {
-  const gitDir = await resolveGitDir(baseDir, options);
-  const excludePath = path.join(gitDir, "info", "exclude");
+  const manager = getGitOperationManager();
+  const excludePath = await manager.executeRead(
+    baseDir,
+    async (git) => {
+      // --git-path resolves to the correct location for both regular repos
+      // and worktrees (where info/exclude is shared via the common dir)
+      const rel = await git.revparse(["--git-path", "info/exclude"]);
+      return path.resolve(baseDir, rel);
+    },
+    { signal: options?.abortSignal },
+  );
 
   let content = "";
   try {
@@ -988,7 +997,7 @@ export async function addToLocalExclude(
     return;
   }
 
-  const infoDir = path.join(gitDir, "info");
+  const infoDir = path.dirname(excludePath);
   await fs.mkdir(infoDir, { recursive: true });
 
   const newContent = content.trimEnd()

packages/git/src/sagas/worktree.ts

@@ -3,6 +3,7 @@ import * as path from "node:path";
 import { GitSaga, type GitSagaInput } from "../git-saga";
 import { addToLocalExclude, branchExists, getDefaultBranch } from "../queries";
 import { safeSymlink } from "../utils";
+import { processWorktreeInclude, runPostCheckoutHook } from "../worktree";
 
 export interface CreateWorktreeInput extends GitSagaInput {
   worktreePath: string;
@@ -35,7 +36,16 @@ export class CreateWorktreeSaga extends GitSaga<
     await this.step({
       name: "create-worktree",
       execute: () =>
-        this.git.raw(["worktree", "add", "-b", branchName, worktreePath, base]),
+        this.git.raw([
+          "-c",
+          "core.hooksPath=/dev/null",
+          "worktree",
+          "add",
+          "-b",
+          branchName,
+          worktreePath,
+          base,
+        ]),
       rollback: async () => {
         try {
           await this.git.raw(["worktree", "remove", worktreePath, "--force"]);
@@ -86,6 +96,18 @@ export class CreateWorktreeSaga extends GitSaga<
       },
     });
 
+    await this.step({
+      name: "process-worktree-include",
+      execute: () => processWorktreeInclude(baseDir, worktreePath),
+      rollback: async () => {},
+    });
+
+    await this.step({
+      name: "run-post-checkout-hook",
+      execute: () => runPostCheckoutHook(baseDir, worktreePath),
+      rollback: async () => {},
+    });
+
     return { worktreePath, branchName, baseBranch: base };
   }
 }
@@ -123,7 +145,14 @@ export class CreateWorktreeForBranchSaga extends GitSaga<
     await this.step({
       name: "create-worktree",
       execute: () =>
-        this.git.raw(["worktree", "add", worktreePath, branchName]),
+        this.git.raw([
+          "-c",
+          "core.hooksPath=/dev/null",
+          "worktree",
+          "add",
+          worktreePath,
+          branchName,
+        ]),
       rollback: async () => {
         try {
           await this.git.raw(["worktree", "remove", worktreePath, "--force"]);
@@ -171,6 +200,18 @@ export class CreateWorktreeForBranchSaga extends GitSaga<
       },
     });
 
+    await this.step({
+      name: "process-worktree-include",
+      execute: () => processWorktreeInclude(baseDir, worktreePath),
+      rollback: async () => {},
+    });
+
+    await this.step({
+      name: "run-post-checkout-hook",
+      execute: () => runPostCheckoutHook(baseDir, worktreePath),
+      rollback: async () => {},
+    });
+
     return { worktreePath, branchName };
   }
 }

packages/git/src/utils.ts

@@ -1,3 +1,4 @@
+import { execFile } from "node:child_process";
 import * as fs from "node:fs/promises";
 import * as os from "node:os";
 import * as path from "node:path";
@@ -58,6 +59,54 @@ export async function safeSymlink(
   }
 }
 
+/**
+ * copy file or directory, use copy-on-write, fall back to cp
+ */
+export async function clonePath(
+  source: string,
+  destination: string,
+): Promise<boolean> {
+  try {
+    await fs.access(source);
+  } catch {
+    return false;
+  }
+
+  const parentDir = path.dirname(destination);
+  await fs.mkdir(parentDir, { recursive: true });
+
+  const platform = os.platform();
+
+  try {
+    if (platform === "darwin") {
+      await execFileAsync("cp", ["-c", "-a", source, destination]);
+    } else {
+      await execFileAsync("cp", ["--reflink=auto", "-a", source, destination]);
+    }
+    return true;
+  } catch {
+    // CoW not supported, fall back to regular copy
+  }
+
+  await fs.cp(source, destination, { recursive: true });
+  return true;
+}
+
+function execFileAsync(
+  command: string,
+  args: string[],
+): Promise<{ stdout: string; stderr: string }> {
+  return new Promise((resolve, reject) => {
+    execFile(command, args, (error, stdout, stderr) => {
+      if (error) {
+        reject(error);
+        return;
+      }
+      resolve({ stdout, stderr });
+    });
+  });
+}
+
 export function parseGitHubUrl(url: string): GitHubRepo | null {
   // Trim whitespace/newlines that git commands may include
   const trimmedUrl = url.trim();