fix(server): detect git repo from subdirectories so diffs and checkpoints work in monorepos

apps/server/src/git/Utils.ts

@@ -1,6 +1,9 @@
 import { existsSync } from "node:fs";
-import { join } from "node:path";
+import { dirname, join } from "node:path";
 
-export function isGitRepository(cwd: string): boolean {
-  return existsSync(join(cwd, ".git"));
+export function isGitRepository(current: string): boolean {
+  do {
+    if (existsSync(join(current, ".git"))) return true;
+  } while (current !== (current = dirname(current)));
+  return false;
 }