Add GitHub thread reply guidance to receiving-code-review

When replying to inline review comments, use the thread API rather than
posting top-level PR comments.

Based on feedback from @ralphbean in PR #79.

RELEASE-NOTES.md

@@ -1,6 +1,6 @@
 # Superpowers Release Notes
 
-## v4.0.1 (2025-12-22)
+## v4.0.1 (2025-12-23)
 
 ### Fixes
 
@@ -12,6 +12,10 @@ Fixed a confusing pattern where Claude would invoke a skill via the Skill tool,
 - Changed "read the skill" → "invoke the skill" in instructions
 - Updated slash commands to use fully qualified skill names (e.g., `superpowers:brainstorming`)
 
+**Added GitHub thread reply guidance to receiving-code-review** (h/t @ralphbean)
+
+Added a note about replying to inline review comments in the original thread rather than as top-level PR comments.
+
 ## v4.0.0 (2025-12-17)
 
 ### New Features

skills/receiving-code-review/SKILL.md

@@ -200,6 +200,10 @@ You understand 1,2,3,6. Unclear on 4,5.
 ✅ "Understand 1,2,3,6. Need clarification on 4 and 5 before implementing."
 ```
 
+## GitHub Thread Replies
+
+When replying to inline review comments on GitHub, reply in the comment thread (`gh api repos/{owner}/{repo}/pulls/{pr}/comments/{id}/replies`), not as a top-level PR comment.
+
 ## The Bottom Line
 
 **External feedback = suggestions to evaluate, not orders to follow.**