docs(inception): using-scribe skill teaches the inception questions; plugin 0.1.38; api-reference + README (#2884, milestone 297 step 6)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/api-reference.md

@@ -76,7 +76,9 @@ endpoint at `/mcp`, not these REST routes.
 | Method | Path | Description |
 |--------|------|-------------|
 | GET / POST | `/api/projects` | List (owned + shared) / create |
-| GET / PATCH / DELETE | `/api/projects/:id` | Read (with `milestone_summary`) / update / delete |
+| GET / PATCH / DELETE | `/api/projects/:id` | Read (with `milestone_summary`, `inception`) / update / delete |
+| POST | `/api/projects/:id/inception` | Record what the project inherits `{choices: {exclude_always_on_rulebooks, subscribe_rulebooks, design_system_id, seed_systems}}` (owner-only; `POST /api/projects` accepts the same under `inception`) |
+| GET | `/api/projects/:id/inception/defaults` | What binds if nobody decides — the inception card's payload |
 | GET | `/api/projects/:id/notes` | Notes + tasks in this project |
 | GET / POST | `/api/projects/:id/milestones` | List / create milestones |
 | GET / PATCH / DELETE | `/api/projects/:id/milestones/:mid` | Read / update / delete |
@@ -118,6 +120,7 @@ endpoint at `/mcp`, not these REST routes.
 | POST | `/api/projects/:id/rules` | Create a project-scoped rule |
 | POST / DELETE | `/api/projects/:id/suppressions/rules/:rid` | Suppress / unsuppress a rule |
 | POST / DELETE | `/api/projects/:id/suppressions/topics/:tid` | Suppress / unsuppress a topic |
+| POST / DELETE | `/api/projects/:id/exclusions/rulebooks/:rid` | Exclude / include an always-on rulebook for this project (inception) |
 
 ## Sharing