test(11.1-06): plant one fixture per docs checker rule and run them in the gate

- testdata/clean passes every check; 63 violation cases each overlay one
  fault and a want.txt naming the single problem it must produce
- TestPlantedViolations also plants the forbidden name (split literals)
  and symlink escapes at run time; TestBuildOutputGuard covers --out
- check-phase11.1.sh --self-test runs the corpus through a go test -json
  detector that refuses FAIL, SKIP, zero tests and no tests to run
- the self-test scratch copy now carries examples/ and README.md, so its
  baseline sees the example command literals the real tree sees

internal/docsite/testdata/clean/docs/guide/start.md

@@ -0,0 +1,32 @@
+---
+title: Start
+description: "Install the demo and greet someone."
+section: guide
+order: 10
+---
+# Start
+
+The demo module greets people.
+
+## Install
+
+Build the docs with `summer docs:build`, or run the application:
+
+```sh
+$ summer docs:build --out site
+./bin/demo serve --addr 127.0.0.1:8080
+```
+
+## Greet someone
+
+Call `demo.Hello`:
+
+```go src=modules/demo/example_test.go#ExampleHello
+fmt.Println(demo.Hello("blog"))
+// Output: Hello, blog
+```
+
+> [!TIP]
+> The [demo reference](../../modules/demo/README.md#usage) lists the whole API.
+
+Continue with [configuration](config.md) or jump back to [install](#install).