fix(proof): E2E comments are not Python either (#952)

CI review follow-up. The E2E template's {title}/{description} sit in '//'
comments, but they were still getting _inline's backslash-doubling — which a
JS comment shows verbatim. My own docstring said 'per context, applied once',
and that was the one context still getting the wrong escaper.

_MARKDOWN_GATES becomes _NON_PYTHON_GATES and includes E2E. Only the Python
templates need doubling; {title_js} stays on _js_string, being the one field
that really is a string literal.

Author: frankbria

codeframe/core/proof/stubs.py

@@ -177,9 +177,12 @@ def _slugify(text: str) -> str:
     return slugify(text)
 
 
-#: Gates whose template is markdown, where none of the Python/JS escaping
-#: applies — the text is rendered as prose.
-_MARKDOWN_GATES = frozenset({Gate.DEMO, Gate.MANUAL})
+#: Gates whose template is not Python, so ``{title}``/``{description}`` need
+#: only line-collapsing: DEMO/MANUAL render the text as markdown prose, and
+#: E2E puts it in ``//`` comments. Backslash-doubling would show up verbatim in
+#: all three. (E2E's ``{title_js}`` is separate — that one is a real string
+#: literal and gets ``_js_string``.)
+_NON_PYTHON_GATES = frozenset({Gate.DEMO, Gate.MANUAL, Gate.E2E})
 
 
 def _collapse(text: str) -> str:
@@ -253,10 +256,10 @@ def generate_stubs(req: Requirement) -> dict[Gate, str]:
         gate = obligation.gate
         template = _TEMPLATES.get(gate, _TEMPLATES[Gate.UNIT])
         # Escaping is chosen by the template's language and applied exactly
-        # once. Markdown renders the text as prose, so it wants neither the
-        # Python backslash-doubling nor JSON escaping; ``title_js`` always
+        # once. Only the Python templates need backslash-doubling; markdown
+        # prose and JS comments would show it verbatim. ``title_js`` always
         # starts from the raw title for the same reason.
-        escape = _collapse if gate in _MARKDOWN_GATES else _inline
+        escape = _collapse if gate in _NON_PYTHON_GATES else _inline
         content = template.format(
             req_id=req.id,
             title=escape(req.title),

tests/core/test_proof9_evidence_integrity_952.py

@@ -661,3 +661,13 @@ def test_markdown_stubs_show_the_original_text(self, gate):
         assert self.RAW_TITLE in content
         if gate is Gate.MANUAL:
             assert self.RAW_DESC in content
+
+    def test_the_e2e_comments_show_the_original_text(self):
+        """E2E's title/description live in `//` comments, not Python
+        docstrings, so they want no backslash-doubling either — only the
+        `title_js` string literal needs JSON escaping."""
+        content = self._stubs([Gate.E2E])[Gate.E2E]
+        comments = [ln for ln in content.splitlines() if ln.lstrip().startswith("//")]
+
+        assert any(self.RAW_TITLE in ln for ln in comments), comments
+        assert any(self.RAW_DESC in ln for ln in comments), comments