docs(marketplace): documentation cleanup, version alignment, architecture doc

- Delete orphan files (.doc-guardian-queue, stale backup, switch-profile.sh)
- Delete stale doc folders (architecture/, designs/, prompts/)
- Create consolidated docs/ARCHITECTURE.md for v9.1.0
- Bump all 12 original plugin versions to 9.0.1
- Fix project-hygiene descriptions (no longer a hook)
- Normalize /rfc, /project, /adr command rows in all docs
- Update CANONICAL-PATHS.md, UPDATING.md, README.md, CLAUDE.md
- COMMANDS-CHEATSHEET.md expanded to one row per sub-command

Version: 9.1.0

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/project-hygiene/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "project-hygiene",
-  "version": "0.1.0",
-  "description": "Post-task cleanup hook that removes temp files, warns about unexpected root files, and manages orphaned supporting files",
+  "version": "9.0.1",
+  "description": "Manual project hygiene checks — temp files, misplaced files, empty dirs, debug artifacts",
   "author": {
     "name": "Leo Miranda",
     "email": "leobmiranda@gmail.com"
@@ -12,10 +12,11 @@
   "keywords": [
     "cleanup",
     "hygiene",
-    "automation",
-    "hooks",
-    "maintenance"
+    "maintenance",
+    "manual-check"
   ],
   "domain": "core",
-  "commands": ["./commands/"]
+  "commands": [
+    "./commands/"
+  ]
 }