Implement Phases 1-5: skeleton, OAuth, categories, video sync/feed, playback

- FastAPI + PostgreSQL + Alembic + React/Vite skeleton, Docker Compose, healthcheck
- Google OAuth (single allowed account), encrypted refresh token storage
- Subscriptions sync with pagination, uploads playlist batch fetch
- Categories CRUD, many-to-many channel assignment, category filtering
- Video sync (playlistItems + videos.list batching), cached feed with cursor
  pagination, background scheduler (APScheduler)
- Video detail page with YouTube embed player
- SPA fallback routing, optimistic UI updates, client-side query caching

40 backend tests covering OAuth allow-list, sync idempotency, cascade deletes,
cursor pagination, and category filtering.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

migrations/env.py

@@ -0,0 +1,50 @@
+import sys
+from logging.config import fileConfig
+from pathlib import Path
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "backend"))
+
+from app.config import settings  # noqa: E402
+from app.db import Base  # noqa: E402
+from app import models  # noqa: E402,F401
+
+config = context.config
+config.set_main_option("sqlalchemy.url", settings.database_url)
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,26 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

migrations/versions/0001_app_settings.py

@@ -0,0 +1,36 @@
+"""app_settings baseline
+
+Revision ID: 0001_app_settings
+Revises:
+Create Date: 2026-09-16
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "0001_app_settings"
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "app_settings",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("key", sa.String(length=255), nullable=False),
+        sa.Column("value", sa.String(), nullable=True),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+        sa.UniqueConstraint("key", name="uq_app_settings_key"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("app_settings")

migrations/versions/0002_oauth_and_channels.py

@@ -0,0 +1,50 @@
+"""oauth_credentials and channels
+
+Revision ID: 0002_oauth_channels
+Revises: 0001_app_settings
+Create Date: 2026-09-16
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "0002_oauth_channels"
+down_revision: Union[str, None] = "0001_app_settings"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "oauth_credentials",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("google_email", sa.String(length=255), nullable=False),
+        sa.Column("encrypted_refresh_token", sa.String(), nullable=False),
+        sa.Column("access_token_expires_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+
+    op.create_table(
+        "channels",
+        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
+        sa.Column("youtube_channel_id", sa.String(length=64), nullable=False),
+        sa.Column("title", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("thumbnail_url", sa.String(), nullable=True),
+        sa.Column("uploads_playlist_id", sa.String(length=64), nullable=True),
+        sa.Column("subscribed", sa.Boolean(), nullable=False, server_default=sa.true()),
+        sa.Column("last_synced_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("youtube_channel_id", name="uq_channels_youtube_channel_id"),
+    )
+    op.create_index("ix_channels_youtube_channel_id", "channels", ["youtube_channel_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_channels_youtube_channel_id", table_name="channels")
+    op.drop_table("channels")
+    op.drop_table("oauth_credentials")

migrations/versions/0003_categories.py

@@ -0,0 +1,46 @@
+"""categories and channel_categories
+
+Revision ID: 0003_categories
+Revises: 0002_oauth_channels
+Create Date: 2026-09-16
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "0003_categories"
+down_revision: Union[str, None] = "0002_oauth_channels"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "categories",
+        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("slug", sa.String(length=255), nullable=False),
+        sa.Column("sort_order", sa.Integer(), nullable=False, server_default="0"),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("name", name="uq_categories_name"),
+        sa.UniqueConstraint("slug", name="uq_categories_slug"),
+    )
+
+    op.create_table(
+        "channel_categories",
+        sa.Column("channel_id", sa.Integer(), sa.ForeignKey("channels.id"), primary_key=True),
+        sa.Column(
+            "category_id",
+            sa.Integer(),
+            sa.ForeignKey("categories.id", ondelete="CASCADE"),
+            primary_key=True,
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("channel_categories")
+    op.drop_table("categories")

migrations/versions/0004_videos.py

@@ -0,0 +1,44 @@
+"""videos
+
+Revision ID: 0004_videos
+Revises: 0003_categories
+Create Date: 2026-09-16
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "0004_videos"
+down_revision: Union[str, None] = "0003_categories"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "videos",
+        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
+        sa.Column("youtube_video_id", sa.String(length=32), nullable=False),
+        sa.Column("channel_id", sa.Integer(), sa.ForeignKey("channels.id"), nullable=False),
+        sa.Column("title", sa.String(length=500), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("thumbnail_url", sa.String(), nullable=True),
+        sa.Column("published_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("duration_seconds", sa.Integer(), nullable=True),
+        sa.Column("youtube_url", sa.String(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("youtube_video_id", name="uq_videos_youtube_video_id"),
+    )
+    op.create_index("ix_videos_youtube_video_id", "videos", ["youtube_video_id"])
+    op.create_index("ix_videos_channel_id", "videos", ["channel_id"])
+    op.create_index("ix_videos_published_at", "videos", ["published_at"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_videos_published_at", table_name="videos")
+    op.drop_index("ix_videos_channel_id", table_name="videos")
+    op.drop_index("ix_videos_youtube_video_id", table_name="videos")
+    op.drop_table("videos")