docs(openclaw): document KG supersede in skill

[ggettert]

Summary

• streamline the OpenClaw MemPalace skill so the loaded SKILL.md is behavior-first instead of a full MCP tool catalog
• move detailed setup and tool-selection guidance into integrations/openclaw/references/
• update the OpenClaw protocol to use mempalace_kg_supersede for single-valued fact replacements
• add unhappy paths and anti-patterns for common agent mistakes: guessing from model memory, over-broad search queries, re-mining before repair/reconnect, and unsafe bulk cleanup

Why

This keeps the main skill focused on runtime behavior: when to use MemPalace, how to choose KG vs drawers, and what mistakes to avoid. Detailed setup and tool-selection notes live in references so they remain available without expanding the primary skill prompt.

Validation

• parsed integrations/openclaw/SKILL.md frontmatter with PyYAML
• verified version is 3.7.0
• verified mempalace_kg_supersede is present
• verified the old invalidate+add replacement rule is absent
• CI passing

Part of #2236

[ggettert]

going to open a new PR to see if I can get the workflows running