add get_own_posts tool, warn against list_records pagination
phi kept looping on list_records (paginating its own posts via pdsx MCP),
exhausting the 50-request limit with no response. get_own_posts wraps
BotClient.get_own_posts() in a single call. operational instructions now
explicitly warn against repeated list_records pagination.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>