chore: update .beads/.gitignore with additional entries

- Add sync-state.json, last-touched to ignores
- Add redirect file ignore (worktree paths)
- Update comments explaining why negation patterns removed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.beads/.gitignore

@@ -10,6 +10,8 @@ daemon.lock
 daemon.log
 daemon.pid
 bd.sock
+sync-state.json
+last-touched
 
 # Local version tracking (prevents upgrade notification spam after git ops)
 .local_version
@@ -18,6 +20,10 @@ bd.sock
 db.sqlite
 bd.db
 
+# Worktree redirect file (contains relative path to main repo's .beads/)
+# Must not be committed as paths would be wrong in other clones
+redirect
+
 # Merge artifacts (temporary files from 3-way merge)
 beads.base.jsonl
 beads.base.meta.json
@@ -26,8 +32,8 @@ beads.left.meta.json
 beads.right.jsonl
 beads.right.meta.json
 
-# Keep JSONL exports and config (source of truth for git)
-!issues.jsonl
-!interactions.jsonl
-!metadata.json
-!config.json
+# NOTE: Do NOT add negation patterns (e.g., !issues.jsonl) here.
+# They would override fork protection in .git/info/exclude, allowing
+# contributors to accidentally commit upstream issue databases.
+# The JSONL files (issues.jsonl, interactions.jsonl) and config files
+# are tracked by git by default since no pattern above ignores them.