Materialize post-shaped routes as posts so generated query loops have content

## Symptom

Importing https://www.360chiro.co.uk/ (Wix) captured the blog post route `post/can-chiropractic-help-with-back-pain-360-chiro-clinic-sheffield/`. The site plan materialized it as a WordPress **page** (post_type=page, nested under an auto-created empty placeholder parent page `post`, which is published). The generated theme's blog template contains a `core/query` loop over posts — which has zero posts to show, so the blog listing renders through `query-no-results` while the actual article lives as a page.

Resulting state (from wp_posts):

- 16 published pages, including `post` (105 bytes, a single empty group) and `can-chiropractic-help-with-back-pain-...` (the article, as a page)
- 0 published posts
- templates: `front-page.html`, `index.html` (with query loop), `page.html`

## Expected

Post-shaped routes (here even URL-prefixed `post/…`) should materialize as posts so the generated query loop has content, no placeholder parent page is needed, and the blog paradigm survives the migration.

Related (not duplicates): #908 tracks the reverse over-classification (bare article landmarks inferred as posts), #1142 shows plans that do create posts need a `single.html` template. Whatever classification signal decides page-vs-post evidently declined here despite the `post/` route prefix and article semantics.

Start by tracing the page-vs-post classification and materialization path for the captured Wix route, using the reported wp_posts state as the baseline. Compare the generated front-page.html, index.html, and page.html templates and the core/query loop behavior. Done means the post-shaped route becomes a published post, no empty post parent page is created, and the blog listing contains the article.

Written by the indexing model from the issue text.