fix: 补建缺失的 Alembic 迁移文件 026-029

生产 DB 已执行过 026-029 迁移但文件丢失（可能 rebase 导致），
导致 alembic 报 'Can't locate revision identified by 029_user_phone'。

补建内容：
- 026: users 表加 name, avatar, updated_at
- 027: users 表加 ban_reason, ban_at
- 028: users 表加 admin_status, admin_remarks
- 029: users 表加 phone

所有 upgrade 做幂等检查（IF NOT EXISTS），安全用于已有字段的库。

alembic/versions/026_add_user_profile_fields.py

@@ -0,0 +1,54 @@
+"""Add user profile fields (name, avatar, updated_at)
+
+Revision ID: 026
+Revises: 025
+Create Date: 2026-07-05
+
+补录用户资料字段。生产数据库已手动添加过这些字段，
+因此 upgrade 做幂等检查，避免在已有字段的库上执行报错。
+"""
+
+import sqlalchemy as sa
+
+from alembic import op
+
+revision = "026"
+down_revision = "025"
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(table: str, column: str) -> bool:
+    conn = op.get_bind()
+    result = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM information_schema.columns " "WHERE table_name = :table AND column_name = :column"
+        ),
+        {"table": table, "column": column},
+    )
+    return result.scalar() > 0
+
+
+def upgrade() -> None:
+    if not _column_exists("users", "name"):
+        op.add_column("users", sa.Column("name", sa.String(100), nullable=True))
+
+    if not _column_exists("users", "avatar"):
+        op.add_column("users", sa.Column("avatar", sa.String(500), nullable=True))
+
+    if not _column_exists("users", "updated_at"):
+        op.add_column(
+            "users",
+            sa.Column(
+                "updated_at",
+                sa.DateTime(),
+                nullable=True,
+                server_default=sa.func.now(),
+            ),
+        )
+
+
+def downgrade() -> None:
+    op.drop_column("users", "updated_at")
+    op.drop_column("users", "avatar")
+    op.drop_column("users", "name")

alembic/versions/027_add_user_ban_fields.py

@@ -0,0 +1,42 @@
+"""Add user ban fields (ban_reason, ban_at)
+
+Revision ID: 027
+Revises: 026
+Create Date: 2026-07-05
+
+补录用户封禁字段。生产数据库已手动添加过这些字段，
+因此 upgrade 做幂等检查。
+"""
+
+import sqlalchemy as sa
+
+from alembic import op
+
+revision = "027"
+down_revision = "026"
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(table: str, column: str) -> bool:
+    conn = op.get_bind()
+    result = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM information_schema.columns " "WHERE table_name = :table AND column_name = :column"
+        ),
+        {"table": table, "column": column},
+    )
+    return result.scalar() > 0
+
+
+def upgrade() -> None:
+    if not _column_exists("users", "ban_reason"):
+        op.add_column("users", sa.Column("ban_reason", sa.Text(), nullable=True))
+
+    if not _column_exists("users", "ban_at"):
+        op.add_column("users", sa.Column("ban_at", sa.DateTime(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "ban_at")
+    op.drop_column("users", "ban_reason")

alembic/versions/028_add_user_admin_fields.py

@@ -0,0 +1,42 @@
+"""Add user admin fields (admin_status, admin_remarks)
+
+Revision ID: 028
+Revises: 027
+Create Date: 2026-07-05
+
+补录管理员备注字段。生产数据库已手动添加过这些字段，
+因此 upgrade 做幂等检查。
+"""
+
+import sqlalchemy as sa
+
+from alembic import op
+
+revision = "028"
+down_revision = "027"
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(table: str, column: str) -> bool:
+    conn = op.get_bind()
+    result = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM information_schema.columns " "WHERE table_name = :table AND column_name = :column"
+        ),
+        {"table": table, "column": column},
+    )
+    return result.scalar() > 0
+
+
+def upgrade() -> None:
+    if not _column_exists("users", "admin_status"):
+        op.add_column("users", sa.Column("admin_status", sa.String(50), nullable=True))
+
+    if not _column_exists("users", "admin_remarks"):
+        op.add_column("users", sa.Column("admin_remarks", sa.Text(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "admin_remarks")
+    op.drop_column("users", "admin_status")

alembic/versions/029_add_user_phone.py

@@ -0,0 +1,38 @@
+"""Add user phone field
+
+Revision ID: 029
+Revises: 028
+Create Date: 2026-07-05
+
+补录用户手机号字段。生产数据库已手动添加过该字段，
+因此 upgrade 做幂等检查。
+"""
+
+import sqlalchemy as sa
+
+from alembic import op
+
+revision = "029"
+down_revision = "028"
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(table: str, column: str) -> bool:
+    conn = op.get_bind()
+    result = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM information_schema.columns " "WHERE table_name = :table AND column_name = :column"
+        ),
+        {"table": table, "column": column},
+    )
+    return result.scalar() > 0
+
+
+def upgrade() -> None:
+    if not _column_exists("users", "phone"):
+        op.add_column("users", sa.Column("phone", sa.String(20), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "phone")