chore(claude): add onboard config — memory, tasks, audit, gitignore

Onboard scaffolding for the dotfiles repo: 5 memory registries,
TODO backlog, onboard audit report, and .gitignore (ignores
Oldconfig, vim swap, .claude/settings.local.json).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/memory/learnings.md

@@ -0,0 +1,13 @@
+# Learnings
+
+Reusable patterns. Caveman + English.
+
+## LRN-001 — Dotfiles installer idempotency pattern
+2026-05-27. Re-runnable installer: `rm -rf` target before each `git clone`, `mkdir -p` dirs,
+back up existing config to fixed `~/Oldconfig` (overwrite prev backup). Avoids "clone fails,
+dir exists" on second run. Apply to any provisioning script.
+
+## LRN-002 — Redundant vim plugin fetch
+2026-05-27. molokai colorscheme committed in `vim/colors/` AND cloned to /tmp then copied.
+`cp -rupv vim/* ~/.vim/` already deploys it. Dropped the clone. Lesson: check what tracked
+files already cover before adding external fetch.