fix: declare PowerMem agent tools in manifest

[Scaxlibur]

Summary

Declare the PowerMem plugin's agent tools in openclaw.plugin.json.

OpenClaw 2026.5.2+ uses openclaw.plugin.json contracts.tools for plugin tool ownership discovery. Without these declarations, runtime-registered tools such as memory_recall and memory_store may not be discoverable or may trigger plugin contract diagnostics in newer OpenClaw versions.

Solution Description

Added a contracts.tools section to openclaw.plugin.json and listed all tools registered by the plugin:

• memory_recall
• memory_store
• memory_forget
• experience_store
• experience_recall
• agent_memory_add
• agent_memory_list
• agent_memory_share
• agent_memory_shared
• cross_scope_share

Validation performed:

• Parsed openclaw.plugin.json successfully
• Compared declared tool names with api.registerTool names in src/index.ts
• Ran npm run lint