fix(shutdown): Improve gastown shutdown reliability

.beads/.gitignore

@@ -32,6 +32,11 @@ beads.left.meta.json
 beads.right.jsonl
 beads.right.meta.json
 
+# Sync state (local-only, per-machine)
+# These files are machine-specific and should not be shared across clones
+.sync.lock
+sync_base.jsonl
+
 # 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.

.beads/config.yaml

@@ -60,10 +60,3 @@
 # - linear.api-key
 # - github.org
 # - github.repo
-sync-branch: beads-sync
-
-# Cross-project dependencies (gt-o3is)
-# Maps project names to paths for external dependency resolution
-# Format: external:<project>:<capability> in bd dep commands
-external_projects:
-  beads: ../../../beads/mayor/rig