Adds back use cases section and example tool queries from the original
docs. Clarifies that built-in memory and Honcho can work together or be
configured separately via memoryMode.
Replaces the stub docs with comprehensive coverage: setup (interactive +
manual), all config fields, memory modes, recall modes, write frequency,
session strategies, host blocks, async prefetch pipeline, dual-peer
architecture, dynamic reasoning, gateway integration, four tools, full
CLI reference, migration paths, and AI peer identity. Trims the Honcho
section in memory.md to a cross-reference.