docs(skills): all skill packs are gitignored, none committed

The owner added /.agents/skills/ to .gitignore, so no skill is in the repository:
the UE packs, the cpp router and blender-director are all local-only. Reconcile the
docs that still said 'in the repository':

- AGENTS.md: blender-director and the UE packs now say gitignored, not committed.
- Docs/toolchain.md: drop the stale 'in this repository' row and name the UE and C++
  sources in the table.
- MEMORY.md: record the decision.

MEMORY.md

@@ -774,3 +774,13 @@ rebuilt body ends up not simulating (`PhysicsType` left at default, not `Simulat
   `/tmp/gigline/vehicle`; the wired block is therefore never reached. Fix the source path
   (or move the FBX) before relying on the import to rebuild the physics asset.
 - Driving (`-drivetest`) is still untested; settling worked only in the transient run.
+
+## 2026-11-10 — All skills are gitignored now (owner)
+
+The owner added `/.agents/skills/` to `.gitignore`, so **no skill pack is committed** —
+the UE packs (`ue-*/`), the `cpp` router and the project's `blender-director` are all
+local-only. This supersedes the earlier "blender-director stays in the repository" wording.
+`AGENTS.md` and `Docs/toolchain.md` are reconciled to say "gitignored, not committed" and to
+name the UE and C++ sources (`quodsoler/unreal-engine-skills` `f3742d7`,
+`DiamonDinoia/skill-cpp` `f2617fb`). The Blender packs remain in the common
+`~/.pi/agent/skills/` root, also outside the repo.