Rename plugin from "ralph-wiggum" to "ralph-loop"

Update all internal references to use "Ralph Loop" as the prominent name
Keep explanatory text noting it "implements the Ralph Wiggum technique"
Rename plugin directory from plugins/ralph-wiggum to plugins/ralph-loop
Update marketplace.json with new plugin name and source path
Update plugin-dev documentation references

plugins/ralph-loop/.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "ralph-loop",
+  "description": "Continuous self-referential AI loops for interactive iterative development, implementing the Ralph Wiggum technique. Run Claude in a while-true loop with the same prompt until task completion.",
+  "author": {
+    "name": "Anthropic",
+    "email": "support@anthropic.com"
+  }
+}