chore(template): clean-slate template snapshot from bb4a0c7

Curated, product-agnostic snapshot of the post-story-04 tree: demo
content deleted, auth-only reference feature, web-next shell, all gates
green. Product-specific docs, ADRs 027-029, PRDs/epics/archive, editor
library traces, and product naming are curated out; generic template
repairs (coverage provider devDeps, root test:coverage script, live
lint fixes, root-only release-please) are kept. See TEMPLATE.md for
provenance, curation list, and usage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

docs/library-decisions/2026-05-14-@testing-library/react.md

@@ -0,0 +1,85 @@
+---
+package: "@testing-library/react"
+version: "^16.0.0"
+tier: core
+decision: approved
+date: 2026-05-14
+deciders: [Danijel Martinek]
+adr: null
+filter-results:
+  license: MIT
+  types: native
+  maintenance: active
+  boundary-fit: pass
+  shadow-check: pass
+  eu-residency: n/a
+  cve-scan: clean
+  named-consumer: pass
+  socketRisk: clean
+verification-commands:
+  - npm view @testing-library/react license
+  - npm view @testing-library/react version
+  - pnpm audit --audit-level=moderate
+accepted-cves: []
+---
+
+## Filter: license
+
+<!-- Result: MIT -->
+
+`npm view @testing-library/react license` returns `MIT`. MIT is on the allowlist.
+
+## Filter: types
+
+<!-- Result: native -->
+
+`@testing-library/react` ships its own TypeScript declaration files. No separate `@types/` package is needed.
+
+## Filter: maintenance
+
+<!-- Result: active -->
+
+Actively maintained by the Testing Library organization. The 16.x line targets React 19. Regular releases; strong community and ecosystem adoption.
+
+## Filter: boundary-fit
+
+<!-- Result: pass -->
+
+`@testing-library/react` is a dependency of `@repo/core-testing`, the workspace's shared testing infrastructure. It provides `render`, `screen`, `fireEvent`, and related utilities for component tests. Feature packages that test UI components use these utilities via `core-testing`. This is the correct placement for shared test infrastructure.
+
+## Filter: shadow-check
+
+<!-- Result: pass -->
+
+`@testing-library/react` is the sole React component testing utility in the workspace. No competing library (Enzyme, React Test Renderer) is present.
+
+## Filter: eu-residency
+
+<!-- Result: n/a -->
+
+`@testing-library/react` is a test utility library with no network communication. EU residency does not apply.
+
+## Filter: cve-scan
+
+<!-- Result: clean -->
+
+`pnpm audit --audit-level=moderate` reports no advisories against `@testing-library/react` at the time of this trace.
+
+## Filter: named-consumer
+
+<!-- Result: pass -->
+
+`@repo/core-testing` uses `@testing-library/react` to provide the `render` utility and `screen` query API for component tests. Feature packages with UI components use these via `core-testing`. Named, non-hypothetical consumer exists today.
+
+## Prompt: replaces
+
+`@testing-library/react` replaces Enzyme and React Test Renderer. Testing Library's philosophy of testing from the user's perspective (querying by role, label, text) produces more resilient tests than implementation-detail-aware approaches.
+
+## Prompt: migration-cost-out
+
+Hard. `render`, `screen`, `fireEvent`, and `userEvent` APIs from Testing Library are used in all component tests. Migrating to a different testing approach requires rewriting all component tests and changing the query strategy (from accessibility-tree queries to DOM selectors or component internals).
+
+## Prompt: alternatives-considered
+
+1. **Enzyme** — Deprecated and no longer maintained for React 18+; Testing Library is the ecosystem standard.
+2. **`react-dom/test-utils`** — Lower-level API without the accessibility-query helpers; more verbose and less idiomatic for testing user behavior.