✨ Compile doc code fences into tests

Every `ts`-tagged fence in README.md / CONTRIBUTING.md now becomes an
executed `node:test` case in a gitignored generated file, so a
documented example cannot drift from the API. The generator hoists and
merges the leading imports, rewrites the library specifier to the
`#test-tiny-pattern-ts` alias, and rejects a fence with no describing
paragraph or one that re-imports a prelude module.

CI regenerates via `pretest:ci`; `create:doc-tests` runs the generator,
formats, then typechecks the output against a scoped tsconfig that
relaxes `noUnusedLocals`. c8's default excludes already omit the
generated `*.test.ts`, so `test:ci` is unchanged.

CONTRIBUTING.md

@@ -22,6 +22,8 @@ the rules so agents and humans don't diverge.
 - **Test:** `npm run test`, `npm run test:ci`
 - **Watch:** `npm run watch` - re-runs tests on file save, humans only
 - **Checks:** `npm run check`, `npm run fix`
+- **Doc tests:** `npm run create:doc-tests` — compile the `ts`-tagged fences
+  in the prose docs into executed, gitignored tests
 - **Verify:** `npm run verify` — the definition of done
 - **Maintenance:** `npm run maintain` — advisory only
 - **Individual fixes:** `npm run fix:oxfmt`, `npm run fix:oxlint`
@@ -87,6 +89,17 @@ Per [AGENTS.md § Never do](./AGENTS.md#never-do), reach green honestly — fix
 types, never suppress the checks you can't make pass. Full rationale:
 [development/testing.md](./development/testing.md).
 
+## Documentation examples
+
+Every `ts`-tagged fence in `README.md` / `CONTRIBUTING.md` is compiled into an
+executed test, so a documented example cannot drift from the API. Describe each
+fence with the paragraph directly above it (that text becomes the test title),
+and keep its library import self-contained;
+`npm run create:doc-tests` regenerates, formats and type-checks the tests under
+`src/doc-test/__generated__/`. CI runs it automatically via `pretest:ci`, so run
+it yourself before `npm run verify` when you touched a fence. Why:
+[development/docs.md](./development/docs.md).
+
 ## Code style and formatting
 
 `oxfmt` is the formatter and `oxlint` is the linter (with type-aware rules).
@@ -115,10 +128,12 @@ intended to run. A `<prefix>:<name>` script is implicitly aggregated by a
 `<prefix>` script (if one exists) and run by the corresponding lefthook hook or
 CI step. Pick the prefix that matches the script's lifecycle:
 
-- `create:*` — front doors of the repo's own workflow; these mutate git state
-  rather than the source. `create:branch` opens a unit of work, `create:finish`
+- `create:*` — front doors of the repo's own workflow; these produce or mutate
+  workflow artifacts (git state, generated doc-tests) rather than the
+  hand-written source. `create:branch` opens a unit of work, `create:finish`
   closes the branch half, `create:release` closes the release half
-  (maintainer-only). No bare `create` aggregator on purpose.
+  (maintainer-only), and `create:doc-tests` regenerates the compiled prose
+  examples. No bare `create` aggregator on purpose.
 - `check:*` — read-only verification; never modifies files. Aggregated by
   `npm run check`.
 - `fix:*` — mutating counterpart of a `check:*` script. Aggregated by