audit fixes: RTK hook, settings unification, graphifyy, statusline

- Add RTK PreToolUse hook (rtk-rewrite.sh) and fix missing config
- Unify settings.json: merge hooks, marketplaces, model into project file
  so link.sh symlink is the single source of truth
- Add statusline: model, folder, git branch, context % progress bar
- Add graphifyy support: detect, install (pipx), lock, doctor, session-start
- Clarify ctx7/ruflo as standalone CLI (not MCP servers)
- Fix install-plugins.sh step numbering (duplicate step 6)
- Add version check in session-start (local vs origin/master)

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

lib/detect-plugins.sh

@@ -67,3 +67,8 @@ detect_ruflo() {
   # Ruflo CLI — installed globally via npm
   command -v ruflo &>/dev/null
 }
+
+detect_graphifyy() {
+  # Graphifyy — codebase knowledge graph, installed via pipx
+  command -v graphify &>/dev/null
+}