chore: ignore tool scratch dirs and the nested friday-voice repo

.playwright-mcp/ and .superpowers/ hold browser console dumps and brainstorm
session state. friday-voice/ is a separate Gitea repo and would otherwise be
committed here as a dangling gitlink.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -17,3 +17,10 @@ Thumbs.db
 .vscode/
 *.swp
 *.swo
+
+# Tool scratch output (not infrastructure)
+.playwright-mcp/
+.superpowers/
+
+# Has its own repo: git.hobbs.farm/jeremy/friday-voice.git
+friday-voice/