Fix sp-stack wiring reference: defineApp().use() not createHost

The api-plugin-* packages mount via @suaveplan/api's defineApp().use(plugin)
(confirmed in api-plugin-payment's quick-start), not the lower-level
createHost() from @suaveplan/api-host. Also make the docs-traversal
fallback root explicit as docs/README.md instead of borrowing sp's
packages/ terminology.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/document-navigator/skills/sp-stack/SKILL.md

@@ -37,9 +37,10 @@ and a booking calendar"*.
 2. **Resolve each capability.**
    - **Manifest hit** → take `primary` + `supporting`; open its `example_doc` under
      `${CLAUDE_PLUGIN_ROOT}/docs/` and read the quick-start block verbatim.
-   - **Manifest miss** → fall back to the `sp` docs-traversal: root README →
-     `<category>/README.md` → `<subcategory>/README.md` → package README, ranking
-     turnkey `api-plugin-*` / engine packages above low-level primitives.
+   - **Manifest miss** → fall back to the `sp` docs-traversal under
+     `${CLAUDE_PLUGIN_ROOT}/docs/`: `docs/README.md` → `<category>/README.md` →
+     `<subcategory>/README.md` → package `README.md`, ranking turnkey `api-plugin-*` /
+     engine packages above low-level primitives.
 
 3. **Assemble.** Dedupe packages, order by dependency (turnkey plugins first), group by
    `layer` (backend / frontend / foundation / devtools).
@@ -53,8 +54,8 @@ and a booking calendar"*.
 
 - **Bill of materials** — grouped by layer, one-line reason per package.
 - **Install** — a single `bun add @suaveplan/… …`.
-- **Wiring** — the `createHost({ plugins: [...] })` composition (see
-  `docs/api-stack/api/api/README.md` for the host entry point).
+- **Wiring** — the `defineApp().use(plugin)` composition from `@suaveplan/api` (see
+  `docs/api-stack/api/api/README.md` for the app entry point).
 - **Starter code** — stitched from the verbatim docs examples.
 - **Gaps & prerequisites** — capabilities with no `@suaveplan` package (the user writes
   custom code or brings a third-party lib) and required external services (API keys,