Add `poc-memory graph spread` command that takes multiple seed node keys,
runs spreading activation through the graph, and returns nodes ranked by
total activation — nodes that bridge multiple seed concepts score highest.
Expose spreading_activation() as pub from the query engine. Add
memory_spread and memory_search_content tool definitions for MCP.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
New src/thought/ module containing tools and infrastructure shared
between poc-agent and subconscious agents: memory operations, file
tools, bash, context window management.
Currently coexists with agent/tools/ — next step is to wire up both
agent/ and subconscious/ to use thought::dispatch instead of
duplicating the routing logic.
Move dbglog macro to lib.rs so it's available crate-wide regardless
of module compilation order.
