docs: separate public manual from internal project documentation

docs/skills.md

@@ -62,8 +62,9 @@ to the reviewer. A correction can reopen the CTE plan without discarding decisio
 
 ## F8: Memory promotion
 
-At the end of the session, the system proposes reusable clarifications. The reviewer decides which
-ones to promote to the global registry, and the session is then finalized.
+At the end of the session, the system proposes reusable Memory cards, including the approved
+solved question. The reviewer selects and edits the additions or updates to retain in the
+workspace's Memory archive, or declines them all. The session is then finalized.
 
 ## Available gates