Initial commit: CI Agent competitive-intelligence monitoring app

FastAPI + Celery + Next.js + Postgres/Redis app with company monitoring,
source collection, LLM-based change analysis, enrichment, and account
security (Turnstile, escalating lockout, email verification).

apps/api/app/db/base.py

@@ -0,0 +1,38 @@
+"""Declarative base + shared mixins for all ORM models."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import UTC, datetime
+
+from sqlalchemy import DateTime
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+
+def utcnow() -> datetime:
+    return datetime.now(UTC)
+
+
+def ensure_aware_utc(value: datetime) -> datetime:
+    """SQLite's `DateTime(timezone=True)` silently drops tzinfo on read back
+    (Postgres does not). Anything read from the DB and compared against an
+    aware `datetime.now(UTC)` must go through this first so the app behaves
+    identically on both backends."""
+    if value.tzinfo is None:
+        return value.replace(tzinfo=UTC)
+    return value
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+class UUIDPrimaryKeyMixin:
+    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4, unique=True)
+
+
+class TimestampMixin:
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=utcnow, onupdate=utcnow
+    )