tool-build: umbrella — remaining designed tools (Grapher/Knowledger/Scaffolder/Advisor/Describer)

[lorenzoliuzzo]

Part of the fleet milestone (#1 §2) — umbrella for the remaining designed-but-
unbuilt tools, kept as one issue (not five) to avoid backlog noise. Each gets its
own issue + repo when picked up. Designs live in mythings-core/docs/tools/.

• MyGrapher — keep a repo's knowledge graph fresh (graphify incremental
  --update only). my-grapher.md.
• MyKnowledger — Q&A over external literature via a separate graphify
  corpus. my-knowledger.md. (Consumer of shortlist seam Add resume/recover loop: never restart an issue from scratch #36.)
• MyScaffolder — bootstrap a new tool repo from a proposal. my-scaffolder.md.
  (Would automate the genesis recipe this milestone did by hand.)
• MyAdvisor — recommend a course of action with trade-offs. my-advisor.md.
  (Consumer of shortlist seam Add resume/recover loop: never restart an issue from scratch #36.)
• MyDescriber — write/improve a PR's title+description after it opens.
  my-describer.md. Blocked by mythings-core#35 (needs diff()).

Also tracked, not yet build-ready (design PR mythings-core#30 not merged):
MyConductor (merge-order advisor) and MySyndicator (cross-repo change fan-out).