docs(17-05): todo for a site cache purge on menu and FAQ saves

.planning/todos/pending/site-cache-purge-for-menu-and-faq.md

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+---
+created: 2026-10-12T16:40:00.000Z
+title: Purge the Nuxt site cache on menu and FAQ admin saves (framework-level purge service)
+area: framework
+severity: minor
+files:
+  - modules/cabana
+  - ../sm-journal-plugin
+  - ../sm-menu-plugin
+  - ../sm-faq-plugin
+  - ../sm-sitemap-plugin
+---
+
+## Problem
+
+Phase 17 (plan 05) moved a site's menu and homepage FAQ onto the menu and FAQ plugins, rendered by the Nuxt layers `vue-menu-layer` and `vue-faq-layer`. The Nuxt app caches pages with Nitro `swr` (300 s on most routes). A Journal post or category save purges that cache: the Journal plugin posts to the Journal layer's `/api/__journal__/cache/purge` route on loopback with a shared token (Phase 16.x). Menu, menu entry and FAQ saves do not, so an editor's change shows only after the TTL (at most 300 s). RESEARCH Open Question 4 left this open; the site's DEPLOY.md ("Blog companions") documents the delay.
+
+The purge today is Journal-specific: the URL and token live under `golem15.journal.site_cache.*`, and the Nuxt route is the Journal layer's. Copying it into every content plugin would give each its own config keys, token and route.
+
+## Solution
+
+1. A framework-level purge service (for example in `backpack` or a small new module) that any plugin can call after a committed admin save: one configured target (`site_cache.purge_url`, `site_cache.purge_token`), the same loopback POST and bearer token, failures logged and never failing the save.
+2. Journal moves onto it, keeping its current keys as aliases for one release.
+3. The menu plugin calls it after a menu or menu entry save, reorder or delete; the FAQ plugin after a FAQ save or delete; the sitemap needs none (it is generated per request).
+4. The purge route moves out of `vue-journal-layer` into a shared place (a tiny layer, or each layer accepting the same route), so a site without Journal still gets purges.
+5. Document the keys in the module README and the site deploy guides.