fix(sandbox): run pnpm on native disk

apps/agent-worker/README.md

@@ -152,6 +152,12 @@ webpack compilation even after the listening socket opens. A baked Python synchr
 full refresh on every process start and mirrors subsequent writes and deletions within one second,
 including shell-based edits. The local source, dependency tree, and build cache are disposable;
 wake and restart reconstruct them from the durable project without changing the Files surface.
+Direct pnpm commands use that same native-disk source as a transaction: the runtime snapshots the
+durable source, executes pnpm locally, and copies only command-produced source changes back after
+verifying that the corresponding durable paths did not change concurrently. Long-running pnpm
+processes keep the durable-to-local mirror alive for hot reload. Shell-wrapped package managers are
+rejected because they cannot participate in this synchronization boundary; npm, Yarn, and Bun stay
+disabled for project workspaces.
 
 AgentRun keeps one compact exact SQLite shape for run identity, replay parts, and
 coordination state. Dormant objects are reconciled transactionally on activation;

apps/agent-worker/src/durable-objects/app-builder-local-preview.ts

@@ -1,95 +1,19 @@
 import { shellQuote } from "../sandbox-support";
-import { NEXT_RUNTIME_BIN, projectLocalSourceDir } from "./project-sandbox-package-runtime";
+import { localProjectProcessCommand } from "./project-sandbox-local-source";
+import { NEXT_RUNTIME_BIN, resolveProjectLocalRuntime } from "./project-sandbox-package-runtime";
 
 interface LocalPreviewCommandInput {
   port: number;
   sourceDir: string;
   workspaceSlug: string;
 }
 
-const PREVIEW_MIRROR_SYNC_SCRIPT = `
-import os
-import shutil
-import sys
-import time
-
-IGNORED_DIRS = {".expo", ".next", "node_modules"}
-LOCAL_ONLY_NAMES = IGNORED_DIRS | {"next-env.d.ts"}
-
-def remove_path(path):
-    if os.path.isdir(path) and not os.path.islink(path):
-        shutil.rmtree(path)
-    elif os.path.lexists(path):
-        os.unlink(path)
-
-def sync_link(source, target):
-    link = os.readlink(source)
-    if os.path.islink(target) and os.readlink(target) == link:
-        return
-    remove_path(target)
-    os.symlink(link, target)
-
-def sync_file(entry, target, force):
-    source_stat = entry.stat(follow_symlinks=False)
-    try:
-        target_stat = os.stat(target, follow_symlinks=False)
-    except FileNotFoundError:
-        target_stat = None
-    changed = (
-        force
-        or target_stat is None
-        or not os.path.isfile(target)
-        or source_stat.st_size != target_stat.st_size
-        or source_stat.st_mtime_ns > target_stat.st_mtime_ns
-    )
-    if changed:
-        remove_path(target)
-        shutil.copy2(entry.path, target, follow_symlinks=False)
-
-def sync_directory(source, target, force=False):
-    if os.path.lexists(target) and not os.path.isdir(target):
-        remove_path(target)
-    os.makedirs(target, exist_ok=True)
-    source_names = set()
-    for entry in os.scandir(source):
-        if entry.name in IGNORED_DIRS:
-            continue
-        source_names.add(entry.name)
-        destination = os.path.join(target, entry.name)
-        try:
-            if entry.is_symlink():
-                sync_link(entry.path, destination)
-            elif entry.is_dir(follow_symlinks=False):
-                sync_directory(entry.path, destination, force)
-            elif entry.is_file(follow_symlinks=False):
-                sync_file(entry, destination, force)
-        except FileNotFoundError:
-            continue
-    for entry in os.scandir(target):
-        if entry.name not in source_names and entry.name not in LOCAL_ONLY_NAMES:
-            remove_path(entry.path)
-
-def synchronize(source, target, force):
-    sync_directory(source, target, force)
-
-source_dir, target_dir, mode = sys.argv[1:4]
-if mode == "once":
-    synchronize(source_dir, target_dir, True)
-else:
-    while True:
-        try:
-            synchronize(source_dir, target_dir, False)
-        except OSError:
-            pass
-        time.sleep(0.75)
-`;
-
 /** Runs Next from native sandbox disk while `/workspace` remains the durable project source. */
 export function localNextPreviewCommand(input: LocalPreviewCommandInput): string[] {
-  const localSourceDir = projectLocalSourceDir(input.workspaceSlug);
-  const syncCommand = ["python3", "-c", PREVIEW_MIRROR_SYNC_SCRIPT, input.sourceDir, localSourceDir]
-    .map(shellQuote)
-    .join(" ");
+  const runtime = resolveProjectLocalRuntime(input.sourceDir);
+  if (!runtime || runtime.workspaceSlug !== input.workspaceSlug) {
+    throw new TypeError("Preview source does not match its workspace slug.");
+  }
   const nextCommand = [
     NEXT_RUNTIME_BIN,
     "dev",
@@ -101,20 +25,5 @@ export function localNextPreviewCommand(input: LocalPreviewCommandInput): string
   ]
     .map(shellQuote)
     .join(" ");
-  const command = [
-    `${syncCommand} once || exit $?`,
-    `${syncCommand} loop &`,
-    "sync_pid=$!",
-    `cd ${shellQuote(localSourceDir)} || exit $?`,
-    `${nextCommand} &`,
-    "app_pid=$!",
-    'terminate() { kill -TERM "$app_pid" "$sync_pid" 2>/dev/null || true; }',
-    "trap terminate HUP INT TERM",
-    'wait "$app_pid"',
-    "status=$?",
-    'kill "$sync_pid" 2>/dev/null || true',
-    'wait "$sync_pid" 2>/dev/null || true',
-    'exit "$status"',
-  ].join("\n");
-  return ["sh", "-lc", command];
+  return ["sh", "-lc", localProjectProcessCommand(runtime, nextCommand)];
 }