fix(api): remove duplicate alembic migrations after merge

Drop legacy 0019_backfill_missing_columns and 0020_backfill_missing_schema
chain so only 0019_align_legacy_schema remains as head.

api/alembic/versions/0019_backfill_missing_columns.py

@@ -1,51 +0,0 @@
-"""补建缺失列：segments.audio_duration_seconds, conversations.deleted_at
-
-0001 用 create_all 建表，对已有表不会 ALTER 追加列。
-本迁移补齐 ORM 模型中存在但生产库缺失的两列。
-
-Revision ID: 0019_backfill_missing_columns
-Revises: 0018_users_language_preference
-"""
-
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-revision: str = "0019_backfill_missing_columns"
-down_revision: Union[str, None] = "0018_users_language_preference"
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def _column_names(table_name: str) -> set[str]:
-    bind = op.get_bind()
-    inspector = sa.inspect(bind)
-    return {column["name"] for column in inspector.get_columns(table_name)}
-
-
-def upgrade() -> None:
-    seg_cols = _column_names("segments")
-    if "audio_duration_seconds" not in seg_cols:
-        op.add_column(
-            "segments",
-            sa.Column("audio_duration_seconds", sa.Integer(), nullable=True),
-        )
-
-    conv_cols = _column_names("conversations")
-    if "deleted_at" not in conv_cols:
-        op.add_column(
-            "conversations",
-            sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
-        )
-
-
-def downgrade() -> None:
-    conv_cols = _column_names("conversations")
-    if "deleted_at" in conv_cols:
-        op.drop_column("conversations", "deleted_at")
-
-    seg_cols = _column_names("segments")
-    if "audio_duration_seconds" in seg_cols:
-        op.drop_column("segments", "audio_duration_seconds")

api/alembic/versions/0020_add_tts_audio_urls_column.py

@@ -1,66 +0,0 @@
-"""补建所有 ORM 模型中存在但数据库缺失的列
-
-0001 用 create_all 建表，对已有表不会 ALTER 追加列。
-本迁移自动内省 ORM 元数据与实际数据库 schema 的差异，
-为每张已有表补齐缺失列（不含 FK 约束，仅补列定义）。
-
-Revision ID: 0020_backfill_all_missing_columns
-Revises: 0019_backfill_missing_columns
-"""
-
-from __future__ import annotations
-
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-revision: str = "0020_backfill_missing_schema"
-down_revision: Union[str, None] = "0019_backfill_missing_columns"
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def _import_all_models() -> None:
-    from app.features.asset import models as _asset  # noqa: F401
-    from app.features.auth import models as _auth  # noqa: F401
-    from app.features.conversation import models as _conv  # noqa: F401
-    from app.features.evaluation import models as _eval  # noqa: F401
-    from app.features.memory import models as _memory  # noqa: F401
-    from app.features.memoir import models as _memoir  # noqa: F401
-    from app.features.payment import models as _payment  # noqa: F401
-    from app.features.story import models as _story  # noqa: F401
-    from app.features.user import models as _user  # noqa: F401
-
-
-def upgrade() -> None:
-    from app.core.db import Base
-
-    _import_all_models()
-
-    bind = op.get_bind()
-    inspector = sa.inspect(bind)
-    existing_tables = set(inspector.get_table_names())
-
-    for table in Base.metadata.sorted_tables:
-        if table.name not in existing_tables:
-            continue
-
-        db_cols = {c["name"] for c in inspector.get_columns(table.name)}
-
-        for col in table.columns:
-            if col.name in db_cols:
-                continue
-
-            kwargs: dict = {"nullable": True}
-
-            if col.server_default is not None:
-                kwargs["server_default"] = col.server_default.arg
-
-            new_col = sa.Column(col.name, col.type, **kwargs)
-            op.add_column(table.name, new_col)
-
-
-def downgrade() -> None:
-    pass