Initial commit: habit tracker PWA with Google OAuth, push notifications

FastAPI + SQLAlchemy/Alembic + MariaDB backend with Jinja2/htmx/Alpine
server-rendered frontend. Multi-user via Google OAuth, daily habit
tracking, monthly/weekly history views, Web Push reminders via
APScheduler, and PWA support (manifest, service worker, offline caching).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

migrations/versions/0003_add_user_table.py

@@ -0,0 +1,34 @@
+"""add user table
+
+Revision ID: 0003_add_user_table
+Revises: 0002_add_condition_text
+Create Date: 2026-07-15
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0003_add_user_table"
+down_revision: Union[str, None] = "0002_add_condition_text"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "user",
+        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
+        sa.Column("google_sub", sa.String(length=255), nullable=False, unique=True),
+        sa.Column("email", sa.String(length=255), nullable=False, unique=True),
+        sa.Column("name", sa.String(length=255), nullable=True),
+        sa.Column("picture_url", sa.String(length=512), nullable=True),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.func.now()),
+        mysql_engine="InnoDB",
+        mysql_charset="utf8mb4",
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("user")