fix(backup): a task claim does not travel in a backup (milestone 381)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/scribe/services/backup.py

@@ -180,7 +180,13 @@ _COLUMN_EXCLUSIONS: dict[str, set[str]] = {
         "forge_connection_id",
     },
     "milestones": {"deleted_at", "deleted_batch_id"},
-    "notes": {"deleted_at", "deleted_batch_id"},
+    "notes": {
+        "deleted_at", "deleted_batch_id",
+        # A claim is a session's attention, not the work's state (milestone
+        # 381). Restoring one would assert that a session on another install,
+        # possibly long gone, is working the task right now.
+        "claimed_by", "claimed_at", "claim_touched_at", "claim_session",
+    },
     "task_logs": set(),
     "note_drafts": set(),
     "note_versions": set(),
@@ -268,7 +274,10 @@ _IMPORT_COLUMN_EXCLUSIONS: dict[str, set[str]] = {
         "design_system_id", "inception",
     },
     "milestones": {"id", "deleted_at", "deleted_batch_id"},
-    "notes": {"id", "deleted_at", "deleted_batch_id"},
+    "notes": {
+        "id", "deleted_at", "deleted_batch_id",
+        "claimed_by", "claimed_at", "claim_touched_at", "claim_session",
+    },
     "task_logs": {"id"},
     "note_drafts": {"id"},
     "note_versions": {"id"},