Add damem notes and skills

.agents/memory/tests-layout-vitest.md

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+---
+description: Vitest via vp test; unit tests sit next to code as *.test.ts, regression/integration tests in tests/ via the public entry; scripts/ has no tests
+---
+
+Decided 2026-10-14 for all repos.
+
+- **Runner:** Vitest through `vp test`. Import test APIs from
+  `vite-plus/test` (`describe`, `expect`, `it`).
+- **Unit tests** sit next to the code: `src/foo/bar.ts` is tested in
+  `src/foo/bar.test.ts`. Vitest's default include finds them; no `test`
+  config needed. Packages publish only `dist/`, so colocated tests cost nothing
+  in the tarball.
+- **Regression and integration tests** live in the top-level `tests/` folder
+  and use only the public entry point (an alias like `#plugin`), never
+  internals. `vp test tests` runs just these.
+- **No in-source tests** (`import.meta.vitest`).
+- **`scripts/` gets no tests** (2026-10-15): it is repo tooling, not
+  production code (`project-lint.ts`, `decorators.ts`, `lit-check.ts`,
+  release helpers).
+- Test files follow every lint rule; no relaxed overrides for tests.
+
+## Migrating Deno tests
+
+`Deno.test` suites were converted by a codemod
+(`~/.local/share/deno-migration/src/convert.ts` on the user's machine), then
+its TODOs finished by hand. Watch for:
+
+- `@std/assert` → `expect` (`assertEquals` → `toStrictEqual` or `toBe`,
+  `assertThrows` → `toThrow`, `assertRejects` → `rejects.toThrow`);
+- `Deno.*` file, env, and process APIs → `node:fs`, `process.env`,
+  `node:child_process`;
+- `t.step` → nested `describe`/`it`;
+- sanitizer options, which Vitest doesn't have.
+
+A migration PR must keep every test case; a dropped case is lost coverage.
+Tests must pass locally before any push.