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.

plugins/config.json

@@ -0,0 +1,3 @@
+{
+  "repositories": {}
+}