fix: align pi dependencies for 0.84.2

[FenjuFu]

Summary

Supersedes #55, which cannot clear CLA because the branch contains both a Dependabot-authored commit and a contributor follow-up. The packages have also advanced from 0.84.1 to 0.84.2 since that PR was opened.

• update @earendil-works/pi-ai and @earendil-works/pi-agent-core together from 0.82.1 to 0.84.2 in both consuming workspaces
• regenerate the pnpm lockfile from current main
• reject the new non-terminal pending stop reason instead of emitting a completed stream
• add a focused regression test for the pending case

Updating the two pi packages together avoids duplicate incompatible pi-ai type versions.

Validation

Passed locally:

• clean
• ESLint
• Prettier check
• full workspace TypeScript build and DTS generation
• focused createOpenClawHostModel rejects non-terminal native completions regression (1/1)
• git diff --check

The full test command reaches the test phase on Windows, but existing platform-specific tests fail on POSIX path expectations (/ vs \\, drive letters) and a Windows concurrent-rename EPERM; these failures are outside the five changed files. The Linux/macOS GitHub matrix will be the authoritative full-suite result.

DCO

The single commit uses FenjuFu's verified GitHub noreply identity and includes the matching Signed-off-by trailer.

[FenjuFu]

The first CI run passed lint and all four Ubuntu/macOS test jobs. K8s E2E reached all three agents and passed 33/34 checks; the only failure was the setup probe invoking the removed hermes version subcommand. The current Hermes CLI advertises --version instead.

Fixed that probe in d0e4594 (hermes --version). Pi 0.84.2 and the memory flows for Hermes, Pi, and OpenClaw all passed in the failed run. Waiting for the refreshed exact-head checks.

[dongjiang1989]

Thanks. Just update package version