Phase 7: serve the vet sample from the template tools and docs

- build.py: _TEMPLATE_COMPONENTS rewritten around the vet sample (53 kinds —
  per-resource slices, jobs, worked appointment_reminder family, tests);
  seed tokens dropped from the manifest ('sample: vet' instead)
- registry.py: get_app_component(kind) no longer renames item/example seeds;
  prompts and tool docs updated to 'copy a slice and adapt'
- templates/README.md, 01_build_recipe, 40_ui_admin, wiki/03 updated off the
  old seed scheme; repo inventory/config now exclude vet (docs move under
  standards; react/vet itself is deleted in a later phase)
- regenerated MCP bundle, vendored templates, and site output

standards/mcp/repos.json

@@ -192,19 +192,6 @@
         "wiki"
       ],
       "mcp": null
-    },
-    {
-      "name": "vet",
-      "type": "app",
-      "path": "react/vet",
-      "version_source": "VERSION",
-      "drone": "service-docker.yaml",
-      "trigger": "tag",
-      "docs": [
-        "lib",
-        "wiki"
-      ],
-      "mcp": null
     }
   ]
 }