fix(server): resolve gh executable via login shell for desktop users

Electron apps on macOS inherit a minimal PATH (/usr/bin:/bin:/usr/sbin:/sbin)
that doesn't include Homebrew or other user-installed tools. This caused
GitHub features (PR status, Create PR) to show as unavailable in the
desktop app even when gh CLI was installed and authenticated.

Extract findExecutable, resolveShellEnv, and related utilities from
provider-launch-config.ts into a shared utils/executable.ts module.
Use findExecutable("gh") with lazy caching so the login-shell resolution
happens once per daemon lifetime. Pass resolveShellEnv() as the process
env for all gh subprocess calls.

Update all consumers to import directly from utils/executable.ts —
no re-exports through provider-launch-config.ts.

packages/server/src/utils/checkout-git.ts

@@ -6,6 +6,7 @@ import { open as openFile, stat as statFile } from "fs/promises";
 import { TTLCache } from "@isaacs/ttlcache";
 import type { ParsedDiffFile } from "../server/utils/diff-highlighter.js";
 import { parseAndHighlightDiff } from "../server/utils/diff-highlighter.js";
+import { findExecutable, resolveShellEnv } from "./executable.js";
 import { isPaseoOwnedWorktreeCwd } from "./worktree.js";
 import { requirePaseoWorktreeBaseRefName } from "./worktree-metadata.js";
 
@@ -23,6 +24,7 @@ const PULL_REQUEST_STATUS_CACHE_MAX = 1_000;
 let pullRequestStatusCacheTtlMs = DEFAULT_PULL_REQUEST_STATUS_CACHE_TTL_MS;
 let pullRequestStatusCache = createPullRequestStatusCache(pullRequestStatusCacheTtlMs);
 const pullRequestStatusInFlight = new Map<string, Promise<PullRequestStatusResult>>();
+let cachedGhPath: string | null | undefined = undefined;
 
 function createPullRequestStatusCache(ttlMs: number) {
   return new TTLCache<string, PullRequestStatusResult>({
@@ -52,6 +54,14 @@ export function __setPullRequestStatusCacheTtlForTests(ttlMs: number): void {
   pullRequestStatusInFlight.clear();
 }
 
+export function __resetGhPathCacheForTests(): void {
+  cachedGhPath = undefined;
+}
+
+export function __setGhPathForTests(path: string | null): void {
+  cachedGhPath = path;
+}
+
 async function execGit(
   command: string,
   options: { cwd: string; env?: NodeJS.ProcessEnv },
@@ -1731,12 +1741,14 @@ export interface PullRequestStatusResult {
   githubFeaturesEnabled: boolean;
 }
 
-async function ensureGhAvailable(cwd: string): Promise<void> {
-  try {
-    await execAsync("gh --version", { cwd });
-  } catch {
-    throw new Error("GitHub CLI (gh) is not available or not authenticated");
+function resolveGhPath(): string {
+  if (cachedGhPath === undefined) {
+    cachedGhPath = findExecutable("gh");
   }
+  if (cachedGhPath === null) {
+    throw new Error("GitHub CLI (gh) is not installed or not in PATH");
+  }
+  return cachedGhPath;
 }
 
 function getCommandErrorText(error: unknown): string {
@@ -1805,7 +1817,7 @@ export async function createPullRequest(
   options: CreatePullRequestOptions,
 ): Promise<{ url: string; number: number }> {
   await requireGitRepo(cwd);
-  await ensureGhAvailable(cwd);
+  const ghPath = resolveGhPath();
   const repo = await resolveGitHubRepo(cwd);
   if (!repo) {
     throw new Error("Unable to determine GitHub repo from git remote");
@@ -1827,13 +1839,14 @@ export async function createPullRequest(
 
   await execAsync(`git push -u origin ${head}`, { cwd });
 
+  const ghEnv = { ...resolveShellEnv(), GIT_TERMINAL_PROMPT: "0" };
   const args = ["api", "-X", "POST", `repos/${repo}/pulls`, "-f", `title=${options.title}`];
   args.push("-f", `head=${head}`);
   args.push("-f", `base=${normalizedBase}`);
   if (options.body) {
     args.push("-f", `body=${options.body}`);
   }
-  const { stdout } = await execFileAsync("gh", args, { cwd });
+  const { stdout } = await execFileAsync(ghPath, args, { cwd, env: ghEnv });
   const parsed = JSON.parse(stdout.trim());
   if (!parsed?.url || !parsed?.number) {
     throw new Error("GitHub CLI did not return PR url/number");
@@ -1875,8 +1888,9 @@ async function getPullRequestStatusUncached(cwd: string): Promise<PullRequestSta
       githubFeaturesEnabled: false,
     };
   }
+  let ghPath: string;
   try {
-    await ensureGhAvailable(cwd);
+    ghPath = resolveGhPath();
   } catch {
     return {
       status: null,
@@ -1885,14 +1899,14 @@ async function getPullRequestStatusUncached(cwd: string): Promise<PullRequestSta
   }
   try {
     const { stdout } = await execFileAsync(
-      "gh",
+      ghPath,
       [
         "pr",
         "view",
         "--json",
         "url,title,state,baseRefName,headRefName,mergedAt",
       ],
-      { cwd },
+      { cwd, env: { ...resolveShellEnv(), GIT_TERMINAL_PROMPT: "0" } },
     );
     const pr = JSON.parse(stdout.trim());
     if (!pr || typeof pr !== "object" || !pr.url || !pr.title) {