#4881: docs(plugin): clarify memory-lancedb is bundled (no npm install needed)

Fixes #4806 ## Problem The plugin documentation may have suggested installing memory-lancedb plugin via `openclaw plugins install @openclaw/memory-lancedb`, which fails with npm 404. This creates confusion as users attempt installation that cannot succeed. ## Root Cause The `memory-lancedb` plugin is **bundled** with OpenClaw and shipped in the npm package under `extensions/memory-lancedb/`. It does not exist on npm registry and should not be installed via `plugins install`. ## Solution Added clarifying note to `docs/plugin.md`: ``` > **Note**: `memory-lancedb` is bundled with OpenClaw and does not need npm installation. > Simply enable it via config: `plugins.slots.memory = "memory-lancedb"` ``` ### Key points: - Plugin is bundled with OpenClaw (included in npm package) - Located in `extensions/memory-lancedb/` directory - Enabled via config: `plugins.slots.memory = "memory-lancedb"` - No `npm install` or `plugins install` needed ## Impact - **Users**: Clear guidance on how to enable memory-lancedb without failed npm attempts - **Confusion reduction**: Prevents 404 errors from attempting non-existent package install - **Correct path**: Directs users to configuration method instead of package installation Fixes #4806 <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates `docs/plugin.md` to clarify that the `memory-lancedb` memory plugin is bundled with OpenClaw and should be enabled via `plugins.slots.memory = "memory-lancedb"` rather than installed from npm, preventing users from hitting npm 404s. The change is localized to the “Available plugins (official)” list, adding a short note next to the existing Memory (LanceDB) entry to steer users toward configuration-based enablement instead of `openclaw plugins install`. <h3>Confidence Score: 4/5</h3> - Mostly safe to merge, but the docs change currently contains obvious markdown artifacts that should be fixed before merging. - The PR is a documentation-only change with low blast radius, but the introduced stray `/` characters will render incorrectly and likely confuse readers, so it needs a quick correction. - docs/plugin.md <!-- greptile_other_comments_section --> **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->