Bug Description

After upgrading OpenClaw to 2026.5.6 via npm install -g openclaw, the Feishu channel goes completely offline with no actionable user-facing error. The gateway starts normally, but openclaw status shows the Feishu channel with an empty State column.

The root cause: feishu was moved from a bundled channel plugin to an external npm package (@openclaw/feishu). The upgrade process does not automatically install this package.

Config warning (passive, easy to miss):

plugins.allow: plugin not installed: feishu — install the official external plugin with: openclaw plugins install @openclaw/feishu

Steps to Reproduce

1. Have OpenClaw 2026.4.27 running with Feishu channel configured and working
2. Run npm install -g openclaw (upgrades to 2026.5.6)
3. Restart the gateway
4. Observe: Feishu channel is gone from the channel status table

Expected Behavior

When a previously-bundled channel plugin has been externalized, the upgrade should:

• Option A: Auto-install the external plugin package during upgrade, OR
• Option B: Fail with a hard user-visible error explaining the channel is offline and how to fix it

Environment

• OpenClaw: 2026.4.27 → 2026.5.6 (npm upgrade)
• OS: macOS 26.4.1 (Darwin arm64)
• Node.js: v25.9.0

Additional Context

Same issue as #77483 (closed) — built-in channel extensions dropped silently during upgrade. This has resurfaced in 2026.5.6 for Feishu. See also #78328.