feat(tasks): parameterize fuzz helpers

- add _invoke_fuzzer() helper so all fuzz tasks share the same runner logic and --long handling.
- make test_fuzz take --input-file/--root-path parameters (defaults to _your_fixture_slug_ template) while keeping the tf alias.
- introduce sdoc_test_fuzz (sdoc_tf) that resolves StrictDoc fixtures by slug, selecting the HTML file automatically or via --html.
- emit clear errors when the StrictDoc docs folder is missing, has no base HTML, or contains multiple candidates without --html.

Author: mettta

tasks.py

@@ -200,21 +200,80 @@ def test_integration(
     run_invoke(context, itest_command)
 
 
-@task(aliases=["tf"])
-def test_fuzz(context, long: bool = False):
+def _invoke_fuzzer(
+    context, input_file: str, root_path: str, long: bool
+) -> None:
     arg_long = "--long" if long else ""
 
     run_invoke(
         context,
         f"""
             python html2pdf4doc/html2pdf4doc_fuzzer.py
-                tests/fuzz/01_strictdoc_guide_202510/strictdoc/docs/strictdoc_01_user_guide-PDF.html
-                tests/fuzz/01_strictdoc_guide_202510/
+                {input_file}
+                {root_path}
                 {arg_long}
         """,
     )
 
 
+def _resolve_strictdoc_fixture(
+    fixture: str, html: Optional[str]
+) -> tuple[str, str]:
+    root_path = os.path.join("tests", "fuzz", fixture)
+    docs_dir = Path(root_path, "strictdoc", "docs")
+
+    if not docs_dir.is_dir():
+        raise RuntimeError(
+            f"StrictDoc docs directory does not exist: {docs_dir}"
+        )
+
+    if html is None:
+        html_candidates = sorted(
+            p
+            for p in docs_dir.glob("*.html")
+            if ".mut." not in p.name and not p.name.endswith(".mut.html")
+        )
+        if not html_candidates:
+            raise RuntimeError(
+                f"No HTML fixture found under {docs_dir}. "
+                "Add an HTML file or pass --html explicitly."
+            )
+        if len(html_candidates) > 1:
+            raise RuntimeError(
+                f"Multiple HTML fixtures found under {docs_dir}: "
+                f"{', '.join(p.name for p in html_candidates)}. "
+                "Specify --html=<file> to choose one."
+            )
+        html_path = html_candidates[0]
+    else:
+        html_path = docs_dir / html
+        if not html_path.is_file():
+            raise RuntimeError(f"HTML file does not exist: {html_path}")
+
+    return (str(html_path), f"{root_path}/")
+
+
+@task(aliases=["tf"])
+def test_fuzz(
+    context,
+    input_file: str = "tests/fuzz/_your_fixture_slug_/file_to_mutate.html",
+    root_path: str = "tests/fuzz/_your_fixture_slug_/",
+    long: bool = False,
+):
+    _invoke_fuzzer(context, input_file, root_path, long)
+
+
+@task(name="sdoc_test_fuzz", aliases=["sdoc_tf"])
+def sdoc_test_fuzz(
+    context,
+    fixture: str = "_your_strictdoc_fixture_slug_",
+    html: Optional[str] = None,
+    long: bool = False,
+):
+    input_file, root_path = _resolve_strictdoc_fixture(fixture, html)
+    _invoke_fuzzer(context, input_file, root_path, long)
+
+
 @task(aliases=["t"])
 def test(context):
     test_integration(context)