[FIX] add missing alembic merge-heads migration + ignore .claude/

The upstream sync merge (45a3faa) brought in war_room_teams_and_chat_attachments
on a sibling branch to the dashboard/collab merge head, re-forking the alembic
head into two (b5c6d7e8f9a0, f7a3b9c1d02e) without a reconciling migration.

Author: Che4ter

.gitignore

@@ -34,3 +34,4 @@ certificates/web_certificates/*.key
 local_dev/
 .serena/
 .tokensave
+.claude/

source/app/alembic/versions/0508647a855c_merge_dashboard_collab_and_war_room_heads.py

@@ -0,0 +1,28 @@
+"""Merge dashboard/collab merge head and war_room_teams head
+
+The upstream sync merge brought in war_room_teams_and_chat_attachments
+(f7a3b9c1d02e), based on d5e6f7a8b9c0, on a sibling branch to the
+dashboard/collab merge head (b5c6d7e8f9a0), re-forking the alembic
+head into two.
+
+Revision ID: 0508647a855c
+Revises: b5c6d7e8f9a0, f7a3b9c1d02e
+Create Date: 2026-07-13 00:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = '0508647a855c'
+down_revision = ('b5c6d7e8f9a0', 'f7a3b9c1d02e')
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    pass
+
+
+def downgrade():
+    pass