fix(e2b): address the v7 review round

- restore the parent's AGENTS.md body around this branch's e2b row (the
  replay had resurrected the pre-profile-CLI layout, deleting the api/,
  bundle/, settings/, and credentials/ groups); the fs/lsp row
  condensations stay for the word budget
- aggregate the composite rollback failure, not the original error, when
  private state cleanup also fails — a surviving remote group is no
  longer hidden by a later cleanup error (triple-failure regression)
- own the state directory before the makeDir RPC, matching the terminal
  transaction, so a cancellation racing a committed creation still
  enters cleanup
- drop the hidden pollMs parameter defaults; the schemastery default is
  the one home, and tests pass the cadence explicitly
- restore spawn/spawnTerminal graceMs validation to the seam's
  documented bound (the earlier removal cited subprocess-local as not
  validating; it does), with rejection regressions

packages/e2b/subprocess-e2b/package.json

@@ -28,6 +28,7 @@
     "@deepseek-ai/dsh-e2b": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
     "@deepseek-ai/dsh-subprocess": "^0.0.1",
+    "@deepseek-ai/dsh-timeout": "^0.0.1",
     "cordis": "^4.0.0-rc.7"
   },
   "dependencies": {
@@ -37,6 +38,7 @@
     "@deepseek-ai/dsh-e2b": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-subprocess": "workspace:^",
+    "@deepseek-ai/dsh-timeout": "workspace:^",
     "cordis": "^4.0.0-rc.7"
   }
 }