Walked server/src/, frontend/src/, and crates/, extracting each module's
//! doc-comment to build a directory-level source map. One row per
directory + one row per top-level file.
Replaces the hand-written stopgap from 5d6757dd with content auto-derived
from the codebase, so it stays useful as decomposes happen — the
descriptions come from mod.rs, not from my recollection of where things
live.
Still a stopgap until 819 (auto-generated source-map-gen) lands and gets
wired into the agent spawn path, but the content is closer to what 819
will produce.
dave
bb779a0b0f