fix(skills): escape grill question markers

src/skills/grill/SKILL.md

@@ -67,7 +67,8 @@ When code contradicts the user's claim, quote both the claim and the code behavi
 ## Open-question accounting
 
 Write each open question as its own top-level line.
-Start each line with one prefix, one space, one bracket state, one space, then the title.
+Escape the line prefix with `\` so Markdown does not treat it as a list item.
+Start each line with one escaped prefix, one space, one bracket state, one space, then the title.
 Indent cause notes by two spaces under the changed question.
 Do not nest open questions under other open questions.
 
@@ -102,12 +103,12 @@ Include a cause note for each `+`, `~`, and `[-]` change.
 Use this format:
 
 ```md
-+ [b] Patent explicitness
+\+ [b] Patent explicitness
   Cause: Your answer made patent terms relevant to the license choice.
 ```
 
 ```md
-~ [ ] Copyleft preference
+\~ [ ] Copyleft preference
   Cause: The `src/skills/` exception leaves the rest of the monorepo under the root license.
 ```