fix: vendor per-kind sites in the hub; drop stale blog docs

- collect.py: when a kind points at the shared site root, copy only the
  per-kind subdir (site/lib -> <repo>/lib) instead of the whole site, so
  stray single-site build output never leaks into the hub
- Purge stale collected artifacts (404.html, assets/, search/, sitemaps,
  objects.inv, duplicate mcp/) from every repo dir, matching the cleaned
  source site/ roots
- Refresh collected output from source repos, incl. the khata-app app
- Remove the vendored Blog API docs (config.yml entry + blog/) and its card

omniread/mcp/nav.json

@@ -1,90 +0,0 @@
-[
-  {
-    "module": "omniread",
-    "resource": "doc://modules/omniread"
-  },
-  {
-    "module": "omniread.core",
-    "resource": "doc://modules/omniread.core"
-  },
-  {
-    "module": "omniread.core.content",
-    "resource": "doc://modules/omniread.core.content"
-  },
-  {
-    "module": "omniread.core.parser",
-    "resource": "doc://modules/omniread.core.parser"
-  },
-  {
-    "module": "omniread.core.scraper",
-    "resource": "doc://modules/omniread.core.scraper"
-  },
-  {
-    "module": "omniread.csv",
-    "resource": "doc://modules/omniread.csv"
-  },
-  {
-    "module": "omniread.csv.client",
-    "resource": "doc://modules/omniread.csv.client"
-  },
-  {
-    "module": "omniread.csv.parser",
-    "resource": "doc://modules/omniread.csv.parser"
-  },
-  {
-    "module": "omniread.csv.parser_base",
-    "resource": "doc://modules/omniread.csv.parser_base"
-  },
-  {
-    "module": "omniread.csv.scraper",
-    "resource": "doc://modules/omniread.csv.scraper"
-  },
-  {
-    "module": "omniread.html",
-    "resource": "doc://modules/omniread.html"
-  },
-  {
-    "module": "omniread.html.parser",
-    "resource": "doc://modules/omniread.html.parser"
-  },
-  {
-    "module": "omniread.html.scraper",
-    "resource": "doc://modules/omniread.html.scraper"
-  },
-  {
-    "module": "omniread.pdf",
-    "resource": "doc://modules/omniread.pdf"
-  },
-  {
-    "module": "omniread.pdf.client",
-    "resource": "doc://modules/omniread.pdf.client"
-  },
-  {
-    "module": "omniread.pdf.parser",
-    "resource": "doc://modules/omniread.pdf.parser"
-  },
-  {
-    "module": "omniread.pdf.scraper",
-    "resource": "doc://modules/omniread.pdf.scraper"
-  },
-  {
-    "module": "omniread.xlsx",
-    "resource": "doc://modules/omniread.xlsx"
-  },
-  {
-    "module": "omniread.xlsx.client",
-    "resource": "doc://modules/omniread.xlsx.client"
-  },
-  {
-    "module": "omniread.xlsx.parser",
-    "resource": "doc://modules/omniread.xlsx.parser"
-  },
-  {
-    "module": "omniread.xlsx.parser_base",
-    "resource": "doc://modules/omniread.xlsx.parser_base"
-  },
-  {
-    "module": "omniread.xlsx.scraper",
-    "resource": "doc://modules/omniread.xlsx.scraper"
-  }
-]