Make template/ the source of truth for documented directory trees

[ortizeg]

The last item on the review's tail.

The problem

Each archetype's directory tree was hand-maintained in two places — the archetype README and the published docs page — so both drifted independently of the actual template.

#11 and #15 corrected the archetype READMEs, which left the docs pages as the only stale copy. They documented 78 files no template generates:

Page	Ghosts
data-processing-pipeline	21 (base.py, dataset.py, download.py, configs/, …)
cv-inference-service	13 (serve.py, predictor.py, preprocessing.py, schemas/, docker-compose.yml, …)
model-zoo	13 (MODEL_CARD.md, benchmarks/, model_configs.py, …)
library-package	11 (helpers.py, module.py, api/, guides/, …)
pytorch-training-project	10 (datamodule.py, detector.py, metrics.py, coco.yaml, …)
research-notebook	10 (three example notebooks, utils.py, plots.py, …)

The fix

Regenerated every docs/archetypes/*.md tree directly from the rendered template, so each now describes exactly what whet init produces. 78 → 0 documented-but-absent files.

Also normalized placeholder syntax across the archetype READMEs. Three different spellings were in use:

• ${var} — correct, what string.Template substitutes
• {{var}} — inert; the engine never substitutes it, so cv-inference-service's README was actively misleading
• <var> — invented

All now use ${var}.

Guards

Three tests so the trees can't silently drift again:

• test_readme_tree_matches_template
• test_docs_page_tree_matches_template
• test_readme_uses_real_placeholder_syntax

I verified the tree guard actually bites by planting a ghost entry — it failed with model-zoo README documents files its template does not ship: ['ghost_file.py'] — then restored the file.

Verification

• uv run pytest tests/ → 279 passed (3 new guards)
• ruff / format / mypy --strict / mkdocs build --strict → clean

🤖 Generated with Claude Code