fix(sandbox): prevent E2B workspace upload + lease idle failures (PAPA-382) (#6560)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - Heartbeats run inside managed sandboxes (E2B, Cloudflare Sandbox),
and each run begins by uploading the agent's workspace as a tar archive
> - PAPA-381's E2B runs were failing at 5 and 11 minutes — two distinct
failure modes were entangled: workspace tar extraction errors on Linux,
and sandbox idle/lease timeouts during normal heartbeat gaps
> - Workspace tar extraction failed because macOS bsdtar embeds
`LIBARCHIVE.xattr.*` PAX headers that GNU tar on Linux rejects with
"This does not look like a tar archive"; the existing
`COPYFILE_DISABLE=1` only suppresses AppleDouble `._*` sidecars, not
inline PAX xattr entries
> - E2B sandboxes also expired between heartbeats because `timeoutMs`
defaulted to a short window and was never refreshed per execute, and
Cloudflare sandboxes idled out because `sleepAfter` defaulted to 10
minutes
> - This pull request adds `--no-xattrs` to the workspace tar
invocation, refreshes the E2B sandbox lifetime on each execute and bumps
the default `timeoutMs` to 1h, and raises the Cloudflare `sleepAfter`
default to 1h
> - The benefit is that long-running heartbeat-driven runs (Claude,
Codex, etc.) survive across both their initial workspace upload and the
natural idle gaps between executes on both E2B and Cloudflare

## What Changed

- `packages/adapter-utils/src/sandbox-managed-runtime.ts`: added
`--no-xattrs` to `createTarballFromDirectory` so macOS bsdtar produces a
clean POSIX tar that GNU tar on Linux can extract, with an inline
comment explaining why `COPYFILE_DISABLE=1` alone is insufficient.
- `packages/plugins/sandbox-providers/e2b/src/plugin.ts`: refresh the
sandbox lifetime on every execute (so long runs don't expire mid-job)
and raised the default `timeoutMs` to 1h.
- `packages/plugins/sandbox-providers/e2b/src/manifest.ts` and
`plugin.test.ts`: updated manifest defaults and added regression
coverage for the new behavior.
- `packages/plugins/sandbox-providers/cloudflare/src/config.ts`,
`manifest.ts`, `plugin.test.ts`: raised default `sleepAfter` from 10m to
1h, mirroring the E2B 1h default, and added a regression test asserting
the acquire-lease request body sends `sleepAfter: "1h"` when not
overridden.

## Verification

- `pnpm --filter @paperclipai/plugin-e2b test`
- `pnpm --filter @paperclipai/plugin-cloudflare-sandbox test`
- Locally cherry-picked the `--no-xattrs` fix onto master and confirmed
end-to-end via a real PAPA-381-style heartbeat-driven E2B run that the
workspace upload now extracts cleanly on Linux. The user (board
operator) tested this on master and reported "Ok, that worked."
- Manual reviewer steps: trigger an E2B heartbeat from a macOS host
(this is where the bsdtar xattr headers come from), confirm the
workspace tar extracts on the Linux sandbox side; run a long (>15 min)
Cloudflare sandbox flow and confirm no lost-lease/idle errors between
executes.

## Risks

- Low risk overall.
- `--no-xattrs` is widely supported by both macOS bsdtar and GNU tar
(Linux). Worst case it silently no-ops on a future host that doesn't
support it; in that case the existing failure mode reappears, it doesn't
introduce a new one.
- Raising default `timeoutMs` (E2B) and `sleepAfter` (Cloudflare) from
short values to 1h means sandboxes stay alive longer between executes by
default. This is the intended behavior — operators that want a tighter
idle window can still override via plugin config.
- E2B per-execute sandbox lifetime refresh adds a small API call per
execute; it is bounded by the same client that already handles execute
traffic, so no new dependencies or retry semantics.

## Model Used

- Claude (Anthropic), `claude-opus-4-7`, extended thinking enabled, tool
use enabled (file/grep/git tools and Paperclip control-plane API). Used
to diagnose the dual failure mode (workspace tar PAX xattr headers +
sandbox lifetime), write the fixes and tests, and drive the verification
loop with the board operator.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots (N/A — no UI changes)
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

packages/adapter-utils/src/sandbox-managed-runtime.ts

@@ -138,6 +138,13 @@ async function createTarballFromDirectory(input: {
   const excludeArgs = ["._*", ...(input.exclude ?? [])].flatMap((entry) => ["--exclude", entry]);
   await execTar([
     "-c",
+    // Prevent macOS bsdtar from embedding LIBARCHIVE.xattr.* PAX extended
+    // headers for extended attributes (e.g. com.apple.provenance). GNU tar on
+    // Linux does not recognise these proprietary headers and fails extraction
+    // with "This does not look like a tar archive". COPYFILE_DISABLE=1 (set in
+    // execTar) already suppresses AppleDouble ._* sidecar files; --no-xattrs
+    // additionally suppresses the inline PAX xattr entries.
+    "--no-xattrs",
     ...(input.followSymlinks ? ["-h"] : []),
     "-f",
     input.archivePath,