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/src/wiki/03_start_an_app.md

@@ -40,8 +40,7 @@ From an MCP client connected to the `standards` server:
    **`start_app`** to intake-and-build in one call.
 3. The prompt hands off to `docs://modules/build_recipe`; the agent scaffolds
    with `get_app_template()` and pulls exact files with
-   `get_app_component(kind, resource=..., family=...)`, authoring only the
-   app-specific parts.
+   `get_app_component(kind)`, authoring only the app-specific parts.
 4. To validate the standard without touching a real app, invoke **`trial`**
    (`trial(app_name=..., build_path=...)`) to build into a scratch directory,
    prove it builds, and report findings.