chats: add chat avatars and profile view-only modal

alembic/versions/0021_chat_avatar_url.py

@@ -0,0 +1,26 @@
+"""add avatar url for chats
+
+Revision ID: 0021_chat_avatar_url
+Revises: 0020_attachment_waveform_data
+Create Date: 2026-03-08
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = "0021_chat_avatar_url"
+down_revision: str | None = "0020_attachment_waveform_data"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.add_column("chats", sa.Column("avatar_url", sa.String(length=512), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("chats", "avatar_url")