chore: initial backup of Claude Code configuration

Includes: CLAUDE.md, settings.json, agents, commands, rules, skills,
hooks, contexts, evals, get-shit-done, plugin configs (installed list
and marketplace sources). Excludes credentials, runtime caches,
telemetry, session data, and plugin binary cache.

commands/gsd/cleanup.md

@@ -0,0 +1,18 @@
+---
+name: gsd:cleanup
+description: Archive accumulated phase directories from completed milestones
+---
+<objective>
+Archive phase directories from completed milestones into `.planning/milestones/v{X.Y}-phases/`.
+
+Use when `.planning/phases/` has accumulated directories from past milestones.
+</objective>
+
+<execution_context>
+@C:/Users/yaoji/.claude/get-shit-done/workflows/cleanup.md
+</execution_context>
+
+<process>
+Follow the cleanup workflow at @C:/Users/yaoji/.claude/get-shit-done/workflows/cleanup.md.
+Identify completed milestones, show a dry-run summary, and archive on confirmation.
+</process>