chore(memory): flush runtime memories and promote managed skills

Memory-file flush for the dotfiles-deploy session with the blankpad admin
credential scrubbed to a placeholder; sessions transcripts untracked
(gitignored) since harness transcripts can carry raw secrets.
Managed skills: command-center-dotfiles-import, ssh-fish-host-remote-exec,
stash-supersession-audit-before-drop.

.gitignore

@@ -56,3 +56,6 @@ puppeteer/
 
 # deploy quarantine — never tracked
 .quarantine/
+
+# harness runtime transcripts: local-only, may contain raw session secrets
+agent/sessions/